Replaced .Url with .URL in sidebar.html

layouts/partials/sidebar.html

@@ -10,7 +10,7 @@
     <ul class="sidebar-nav">
       <li><a href="/">Home</a> </li>
       {{ range .Site.Menus.main }}
-        <li><a href="{{.Url}}"> {{ .Name }} </a></li>
+        <li><a href="{{.URL}}"> {{ .Name }} </a></li>
       {{end}}
     </ul>