docs/azurerm: Adding a layout section for ServiceBus (hashicorp#8197)

Author: stack72

website/source/layouts/azurerm.erb

@@ -138,6 +138,15 @@
               </ul>
             </li>
 
+            <li<%= sidebar_current(/^docs-azurerm-resource-servicebus/) %>>
+              <a href="#">ServiceBus</a>
+              <ul class="nav nav-visible">
+                <li<%= sidebar_current("docs-azurerm-resource-servicebus-namespace") %>>
+                  <a href="/docs/providers/azurerm/r/servicebus_namespace.html">azurerm_servicebus_namespace</a>
+                </li>
+              </ul>
+            </li>
+
             <li<%= sidebar_current(/^docs-azurerm-resource-sql/) %>>
               <a href="#">SQL Resources</a>
               <ul class="nav nav-visible">