Add Google Compute Image docs to sidebar.

Docs were originally added in hashicorp#7960, but weren't added to the sidebar.

Author: cblecker

website/source/layouts/google.erb

@@ -53,6 +53,10 @@
 			<a href="/docs/providers/google/r/compute_https_health_check.html">google_compute_https_health_check</a>
 			</li>
 
+			<li<%= sidebar_current("docs-google-compute-image") %>>
+			<a href="/docs/providers/google/r/compute_image.html">google_compute_image</a>
+			</li>
+
 			<li<%= sidebar_current("docs-google-compute-instance") %>>
 			<a href="/docs/providers/google/r/compute_instance.html">google_compute_instance</a>
 			</li>