Revert "Adds support for query parameter "hideMenu" (#170)"

This reverts commit 71d8be5df1.

client-data/board.html

 
 	<div id="loadingMessage">{{translations.loading}}</div>
 
-	<div id="menu" {{#hideMenu}}style="display:none;"{{/hideMenu}}>
+	<div id="menu">
 		<div id="menuItems">
 			<ul id="tools" class="tools">
 				<li class="tool" tabindex="-1">

server/templating.js

     const boardUriComponent = parts[1];
     params["boardUriComponent"] = boardUriComponent;
     params["board"] = decodeURIComponent(boardUriComponent);
-    params["hideMenu"] = parsedUrl.search.includes("hideMenu");
     return params;
   }
 }