docs: Add google_service_account to sidebar

Author: evandbrown

website/source/layouts/google.erb

@@ -24,6 +24,9 @@
 		<ul class="nav nav-visible">
 			<li<%= sidebar_current("docs-google-project") %>>
 			<a href="/docs/providers/google/r/google_project.html">google_project</a>
+            </li>
+            <li<%= sidebar_current("docs-google-service-account") %>>
+			<a href="/docs/providers/google/r/google_service_account.html">google_service_account</a>
 			</li>
 		</ul>
 		</li>