chore: "Doc" menu retains current language #1060

Author: wardbell

public/_includes/_main-nav.jade

@@ -1,3 +1,6 @@
+- var language = current.path[1] || 'ts'
+- if (language !== 'ts' || language !== 'js' || language !== 'dart') { language = 'ts'; }
+
 md-toolbar(class="main-nav background-regal l-pinned-top l-layer-5",scroll-y-offset-element)
   nav
     h1 <a href="/" md-button>Angular <sup>by Google</sup></a>
@@ -6,7 +9,7 @@ md-toolbar(class="main-nav background-regal l-pinned-top l-layer-5",scroll-y-off
 
     ul(ng-class="appCtrl.showMainNav ? 'is-visible' : ''")
       li.l-left <a class="main-nav-button" href="/features.html" md-button>Features</a>
-      li.l-left <a class="main-nav-button" href="/docs/ts/latest/" md-button>Docs</a>
+      li.l-left <a class="main-nav-button" href="/docs/#{language}/latest/" md-button>Docs</a>
       li.l-left <a class="main-nav-button" href="/about/" md-button>About</a>
       li.l-left <a class="main-nav-button" href="/contribute.html" md-button>Contribute</a>
       li.l-left <a class="main-nav-button" href="/support.html" md-button>Support</a>