Implement review changes

css/_variables.scss

 $welcomePageTabContainerDisplay: flex;
 $welcomePageTabContentDisplay: inherit;
 $welcomePageTabButtonsDisplay: flex;
-$welcomePageTabDisplay: inherit;
+$welcomePageTabDisplay: block;
 
 $welcomePageButtonWidth: 51px;
 $welcomePageButtonHeight: 35px;

css/main.scss

 @import 'ringing/ringing';
 @import 'welcome_page';
 @import 'welcome_page_content';
+@import 'welcome_page_settings_toolbar';
 @import 'toolbars';
 @import 'jquery.contextMenu';
 @import 'keyboard-shortcuts';