fix: closes #6784 (#7137)

* fix: closes #6784

* #6784 also fix homepage + subfolder installs

* #6784 fixes suburls as well (ex. /tags/x and /groups/y)

* #6784 more elegant solution @pitaj

and the last time I touch this function, lol

* #6784 regis, final answer

I lied in that last commit

public/src/app.js

@@ -283,12 +283,12 @@ app.cacheBuster = null;
 	};
 
 	function highlightNavigationLink() {
-		var path = window.location.pathname + window.location.search;
+		$('#main-nav li')
-		$('#main-nav li').removeClass('active');
+			.removeClass('active')
-		if (path) {
+			.find('a')
-			$('#main-nav li').removeClass('active').find('a[href="' + path + '"]').parent()
+			.filter(function (i, x) { return window.location.pathname.startsWith(x.getAttribute('href')); })
-				.addClass('active');
+			.parent()
-		}
+			.addClass('active');
 	}
 
 	app.createUserTooltips = function (els, placement) {