fix(nav): extend navbar active link highlighting to non-home pages

The original commit of the feature in abbd540 didn't work when `baseurl`
contained a sub-dir like we have for the docs site.

Fix abbd540
See #991

exampleSite/config/_default/menus.toml

@@ -25,7 +25,7 @@
 
 [[main]]
   name = "Tutorials"
-  url = "/tutorial/"
+  url = "tutorial/"
   weight = 50
 
 [[main]]

exampleSite/content/tutorial/_index.md

@@ -37,7 +37,7 @@ For example, if you delete this folder, you can remove the following from your m
 ```toml
 [[main]]
   name = "Tutorials"
-  url = "/tutorial/"
+  url = "tutorial/"
   weight = 50
 ```
 
@@ -46,6 +46,6 @@ Or, if you are creating an online course, you can rename the `tutorial` folder t
 ```toml
 [[main]]
   name = "My Course"
-  url = "/course/"
+  url = "course/"
   weight = 50
 ```

layouts/partials/navbar.html

@@ -63,11 +63,11 @@
         {{ $is_same_page := $is_link_in_current_path }}
         {{ if gt (len $hash) 0 }}
           {{ $hash = index $hash 0 }}
-          {{ $hash_removed := (replace .URL $hash "") }}
+          {{ $hash_removed := replace .URL $hash "" }}
           {{ if eq (len $hash_removed) 0 }}
             {{ $hash_removed = "/" }}{{/* Add robustness for `/#SECTION` or `#SECTION` in `menus.toml`. */}}
           {{ end }}
-          {{ $is_same_page = eq $current_page.RelPermalink $hash_removed }}
+          {{ $is_same_page = eq (path.Dir $current_page.RelPermalink) (path.Dir ($hash_removed|relLangURL)) }}
         {{ end }}
 
         <li class="nav-item">