Homepage navigation patch (#6301)

* Update layout.ejs

- Added target="_blank" to Chat nav item.

* Update layout.ejs

- Removed "Contribute" from masthead navigation as per discussion with Mike M.

website/views/layouts/layout.ejs

@@ -161,8 +161,7 @@
               <a purpose="mobile-dropdown-toggle" class="d-flex align-items-center mr-4 collapsed" data-toggle="collapse" data-target="#mobileNavbarToggleCommunity">Community</a>
               <div class="d-block">
                 <div id="mobileNavbarToggleCommunity" purpose="mobile-dropdown" class="collapse" data-parent="#mobileDropdowns">
-                  <a href="/slack">Chat</a>
-                  <a href="/docs/contributing">Contribute</a>
+                  <a href="/slack" target="_blank">Chat</a>
                   <a href="/articles">Articles</a>
                   <a href="/handbook">Handbook</a>
                   <a href="/logos">Logos & artwork</a>
@@ -201,8 +200,7 @@
             <div purpose="dropdown-button" class="btn-group">
               <a class="dropdown-toggle d-flex align-items-center py-2 px-3" data-toggle="dropdown">Community</a>
               <div purpose="header-dropdown" class="dropdown-menu">
-                <a class="dropdown-item mb-1" href="/slack">Chat</a>
-                <a class="dropdown-item mb-1" href="/docs/contributing">Contribute</a>
+                <a class="dropdown-item mb-1" href="/slack" target="_blank">Chat</a>
                 <a class="dropdown-item mb-1" href="/articles">Articles</a>
                 <a class="dropdown-item mb-1" href="/handbook">Handbook</a>
                 <a class="dropdown-item" href="/logos">Logos & artwork</a>