Fix up Tutorials landing page and Tutorials left nav. (#8557)

* Fix up Tutorials landing page and Tutorials left nav.

* Add redirects. Fix bullet.

content/en/docs/tutorials/server.js

@@ -0,0 +1,9 @@
+var http = require('http');
+
+var handleRequest = function(request, response) {
+  console.log('Received request for URL: ' + request.url);
+  response.writeHead(200);
+  response.end('Hello World!');
+};
+var www = http.createServer(handleRequest);
+www.listen(8080);