Merge pull request #3248 from clstokes/docs-pp-shell-local

website/docs: Add `shell-local` post-processor to sidebar.

website/source/layouts/docs.erb

@@ -78,6 +78,7 @@
       <li><a href="/docs/post-processors/docker-push.html">docker-push</a></li>
       <li><a href="/docs/post-processors/docker-save.html">docker-save</a></li>
       <li><a href="/docs/post-processors/docker-tag.html">docker-tag</a></li>
+      <li><a href="/docs/post-processors/shell-local.html">Local Shell</a></li>
       <li><a href="/docs/post-processors/vagrant.html">Vagrant</a></li>
       <li><a href="/docs/post-processors/vagrant-cloud.html">Vagrant Cloud</a></li>
       <li><a href="/docs/post-processors/vsphere.html">vSphere</a></li>