feat(HelpOverflowButton): Implement.

interface_config.js

      */
     AUTO_PIN_LATEST_SCREEN_SHARE: 'remote-only'
 
+    /**
+     * The link to the user documentation.
+     */
+    // HELP_LINK: 'https://docs.example.com/video-meetings.html',
+
+
     /**
      * How many columns the tile view can expand to. The respected range is
      * between 1 and 5.

lang/main.json

             "feedback": "Leave feedback",
             "fullScreen": "Toggle full screen",
             "hangup": "Leave the call",
+            "help": "Help",
             "invite": "Invite people",
             "kick": "Kick participant",
             "localRecording": "Toggle local recording controls",
         "exitTileView": "Exit tile view",
         "feedback": "Leave feedback",
         "hangup": "Leave",
+        "help": "Help",
         "invite": "Invite people",
         "login": "Login",
         "logout": "Logout",

react/features/base/icons/svg/help.svg

+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24"><path fill="none" d="M0 0h24v24H0z"/><path d="M11 18h2v-2h-2v2zm1-16C6.48 2 2 6.48 2 12s4.48 10 10 10 10-4.48 10-10S17.52 2 12 2zm0 18c-4.41 0-8-3.59-8-8s3.59-8 8-8 8 3.59 8 8-3.59 8-8 8zm0-14c-2.21 0-4 1.79-4 4h2c0-1.1.9-2 2-2s2 .9 2 2c0 2-3 1.75-3 5h2c0-2.25 3-2.5 3-5 0-2.21-1.79-4-4-4z"/></svg>

react/features/base/icons/svg/index.js

 export { default as IconFeedback } from './feedback.svg';
 export { default as IconFullScreen } from './full-screen.svg';
 export { default as IconHangup } from './hangup.svg';
+export { default as IconHelp } from './help.svg';
 export { default as IconInfo } from './info.svg';
 export { default as IconInvite } from './invite.svg';
 export { default as IconKick } from './kick.svg';

react/features/toolbox/components/web/HelpButton.js

+// @flow
+
+import { createToolbarEvent, sendAnalytics } from '../../../analytics';
+import { translate } from '../../../base/i18n';
+import { IconHelp } from '../../../base/icons';
+import { AbstractButton, type AbstractButtonProps } from '../../../base/toolbox';
+
+declare var interfaceConfig: Object;
+
+/**
+ * Implements an {@link AbstractButton} to open the user documentation in a new window.
+ */
+class HelpButton extends AbstractButton<AbstractButtonProps, *> {
+    accessibilityLabel = 'toolbar.accessibilityLabel.help';
+    icon = IconHelp;
+    label = 'toolbar.help';
+
+    /**
+     * Handles clicking / pressing the button, and opens a new window with the user documentation.
+     *
+     * @private
+     * @returns {void}
+     */
+    _handleClick() {
+        sendAnalytics(createToolbarEvent('help.pressed'));
+        window.open(interfaceConfig.HELP_LINK);
+    }
+
+    /**
+     * Implements React's {@link Component#render()}.
+     *
+     * @inheritdoc
+     * @returns {React$Node}
+     */
+    render(): React$Node {
+        if (typeof interfaceConfig.HELP_LINK === 'string') {
+            return super.render();
+        }
+
+        return null;
+    }
+}
+
+export default translate(HelpButton);

react/features/toolbox/components/web/Toolbox.js

 import AudioMuteButton from '../AudioMuteButton';
 import { isToolboxVisible } from '../../functions';
 import HangupButton from '../HangupButton';
+import HelpButton from './HelpButton';
 import OverflowMenuButton from './OverflowMenuButton';
 import OverflowMenuProfileItem from './OverflowMenuProfileItem';
 import ToolbarButton from './ToolbarButton';
         this._onSetOverflowVisible = this._onSetOverflowVisible.bind(this);
 
         this._onShortcutToggleChat = this._onShortcutToggleChat.bind(this);
-        this._onShortcutToggleFullScreen
-            = this._onShortcutToggleFullScreen.bind(this);
-        this._onShortcutToggleRaiseHand
-            = this._onShortcutToggleRaiseHand.bind(this);
-        this._onShortcutToggleScreenshare
-            = this._onShortcutToggleScreenshare.bind(this);
-        this._onShortcutToggleVideoQuality
-            = this._onShortcutToggleVideoQuality.bind(this);
-        this._onToolbarOpenFeedback
-            = this._onToolbarOpenFeedback.bind(this);
+        this._onShortcutToggleFullScreen = this._onShortcutToggleFullScreen.bind(this);
+        this._onShortcutToggleRaiseHand = this._onShortcutToggleRaiseHand.bind(this);
+        this._onShortcutToggleScreenshare = this._onShortcutToggleScreenshare.bind(this);
+        this._onShortcutToggleVideoQuality = this._onShortcutToggleVideoQuality.bind(this);
+        this._onToolbarOpenFeedback = this._onToolbarOpenFeedback.bind(this);
         this._onToolbarOpenInvite = this._onToolbarOpenInvite.bind(this);
-        this._onToolbarOpenKeyboardShortcuts
-            = this._onToolbarOpenKeyboardShortcuts.bind(this);
-        this._onToolbarOpenSpeakerStats
-            = this._onToolbarOpenSpeakerStats.bind(this);
-        this._onToolbarOpenVideoQuality
-            = this._onToolbarOpenVideoQuality.bind(this);
+        this._onToolbarOpenKeyboardShortcuts = this._onToolbarOpenKeyboardShortcuts.bind(this);
+        this._onToolbarOpenSpeakerStats = this._onToolbarOpenSpeakerStats.bind(this);
+        this._onToolbarOpenVideoQuality = this._onToolbarOpenVideoQuality.bind(this);
         this._onToolbarToggleChat = this._onToolbarToggleChat.bind(this);
-        this._onToolbarToggleFullScreen
-            = this._onToolbarToggleFullScreen.bind(this);
-        this._onToolbarToggleProfile
-            = this._onToolbarToggleProfile.bind(this);
-        this._onToolbarToggleRaiseHand
-            = this._onToolbarToggleRaiseHand.bind(this);
-        this._onToolbarToggleScreenshare
-            = this._onToolbarToggleScreenshare.bind(this);
-        this._onToolbarToggleSharedVideo
-            = this._onToolbarToggleSharedVideo.bind(this);
-        this._onToolbarOpenLocalRecordingInfoDialog
-            = this._onToolbarOpenLocalRecordingInfoDialog.bind(this);
+        this._onToolbarToggleFullScreen = this._onToolbarToggleFullScreen.bind(this);
+        this._onToolbarToggleProfile = this._onToolbarToggleProfile.bind(this);
+        this._onToolbarToggleRaiseHand = this._onToolbarToggleRaiseHand.bind(this);
+        this._onToolbarToggleScreenshare = this._onToolbarToggleScreenshare.bind(this);
+        this._onToolbarToggleSharedVideo = this._onToolbarToggleSharedVideo.bind(this);
+        this._onToolbarOpenLocalRecordingInfoDialog = this._onToolbarOpenLocalRecordingInfoDialog.bind(this);
 
         this.state = {
             windowWidth: window.innerWidth
                     onClick = { this._onToolbarOpenVideoQuality } />,
             this._shouldShowButton('fullscreen')
                 && <OverflowMenuItem
-                    accessibilityLabel =
-                        { t('toolbar.accessibilityLabel.fullScreen') }
-                    icon = { _fullScreen
-                        ? IconExitFullScreen
-                        : IconFullScreen }
+                    accessibilityLabel = { t('toolbar.accessibilityLabel.fullScreen') }
+                    icon = { _fullScreen ? IconExitFullScreen : IconFullScreen }
                     key = 'fullscreen'
                     onClick = { this._onToolbarToggleFullScreen }
-                    text = { _fullScreen
-                        ? t('toolbar.exitFullScreen')
-                        : t('toolbar.enterFullScreen') } />,
+                    text = { _fullScreen ? t('toolbar.exitFullScreen') : t('toolbar.enterFullScreen') } />,
             <LiveStreamButton
                 key = 'livestreaming'
                 showLabel = { true } />,
                 showLabel = { true } />,
             this._shouldShowButton('sharedvideo')
                 && <OverflowMenuItem
-                    accessibilityLabel =
-                        { t('toolbar.accessibilityLabel.sharedvideo') }
+                    accessibilityLabel = { t('toolbar.accessibilityLabel.sharedvideo') }
                     icon = { IconShareVideo }
                     key = 'sharedvideo'
                     onClick = { this._onToolbarToggleSharedVideo }
-                    text = { _sharingVideo
-                        ? t('toolbar.stopSharedVideo')
-                        : t('toolbar.sharedvideo') } />,
+                    text = { _sharingVideo ? t('toolbar.stopSharedVideo') : t('toolbar.sharedvideo') } />,
             this._shouldShowButton('etherpad')
                 && <SharedDocumentButton
                     key = 'etherpad'
                 visible = { this._shouldShowButton('settings') } />,
             this._shouldShowButton('stats')
                 && <OverflowMenuItem
-                    accessibilityLabel =
-                        { t('toolbar.accessibilityLabel.speakerStats') }
+                    accessibilityLabel = { t('toolbar.accessibilityLabel.speakerStats') }
                     icon = { IconPresentation }
                     key = 'stats'
                     onClick = { this._onToolbarOpenSpeakerStats }
             this._shouldShowButton('feedback')
                 && _feedbackConfigured
                 && <OverflowMenuItem
-                    accessibilityLabel =
-                        { t('toolbar.accessibilityLabel.feedback') }
+                    accessibilityLabel = { t('toolbar.accessibilityLabel.feedback') }
                     icon = { IconFeedback }
                     key = 'feedback'
                     onClick = { this._onToolbarOpenFeedback }
                     text = { t('toolbar.feedback') } />,
             this._shouldShowButton('shortcuts')
                 && <OverflowMenuItem
-                    accessibilityLabel =
-                        { t('toolbar.accessibilityLabel.shortcuts') }
+                    accessibilityLabel = { t('toolbar.accessibilityLabel.shortcuts') }
                     icon = { IconOpenInNew }
                     key = 'shortcuts'
                     onClick = { this._onToolbarOpenKeyboardShortcuts }
-                    text = { t('toolbar.shortcuts') } />
+                    text = { t('toolbar.shortcuts') } />,
+            this._shouldShowButton('help')
+                && <HelpButton
+                    key = 'help'
+                    showLabel = { true } />
         ];
     }
 
             case 'invite':
                 return (
                     <OverflowMenuItem
-                        accessibilityLabel =
-                            { t('toolbar.accessibilityLabel.invite') }
+                        accessibilityLabel = { t('toolbar.accessibilityLabel.invite') }
                         icon = { IconInvite }
                         key = 'invite'
                         onClick = { this._onToolbarOpenInvite }
             case 'localrecording':
                 return (
                     <OverflowMenuItem
-                        accessibilityLabel
-                            = { t('toolbar.accessibilityLabel.localRecording') }
+                        accessibilityLabel = { t('toolbar.accessibilityLabel.localRecording') }
                         icon = { IconRec }
                         key = 'localrecording'
-                        onClick = {
-                            this._onToolbarOpenLocalRecordingInfoDialog
-                        }
+                        onClick = { this._onToolbarOpenLocalRecordingInfoDialog }
                         text = { t('localRecording.dialogTitle') } />
                 );
             default:
             t
         } = this.props;
         const overflowMenuContent = this._renderOverflowMenuContent();
-        const overflowHasItems = Boolean(overflowMenuContent.filter(
-            child => child).length);
+        const overflowHasItems = Boolean(overflowMenuContent.filter(child => child).length);
         const toolbarAccLabel = 'toolbar.accessibilityLabel.moreActionsMenu';
         const buttonsLeft = [];
         const buttonsRight = [];
                         && this._renderDesktopSharingButton() }
                     { buttonsLeft.indexOf('raisehand') !== -1
                         && <ToolbarButton
-                            accessibilityLabel =
-                                {
-                                    t('toolbar.accessibilityLabel.raiseHand')
-                                }
+                            accessibilityLabel = { t('toolbar.accessibilityLabel.raiseHand') }
                             icon = { IconRaisedHand }
                             onClick = { this._onToolbarToggleRaiseHand }
                             toggled = { _raisedHand }
                     { buttonsLeft.indexOf('chat') !== -1
                         && <div className = 'toolbar-button-with-badge'>
                             <ToolbarButton
-                                accessibilityLabel =
-                                    { t('toolbar.accessibilityLabel.chat') }
+                                accessibilityLabel = { t('toolbar.accessibilityLabel.chat') }
                                 icon = { IconChat }
                                 onClick = { this._onToolbarToggleChat }
                                 toggled = { _chatOpen }