Update GitLab architecture diagram, include Google draw link

[ci skip]

doc/development/architecture.md

@@ -54,6 +54,8 @@ To serve repositories over SSH there's an add-on application called gitlab-shell
 
 ![GitLab Diagram Overview](gitlab_architecture_diagram.png)
  
+_[edit diagram](https://docs.google.com/drawings/d/1fBzAyklyveF-i-2q-OHUIqDkYfjjxC4mq5shwKSZHLs/edit)_
+
 A typical install of GitLab will be on GNU/Linux. It uses Nginx or Apache as a web front end to proxypass the Unicorn web server. By default, communication between Unicorn and the front end is via a Unix domain socket but forwarding requests via TCP is also supported. The web front end accesses `/home/git/gitlab/public` bypassing the Unicorn server to serve static pages, uploads (e.g. avatar images or attachments), and precompiled assets. GitLab serves web pages and a [GitLab API](https://gitlab.com/gitlab-org/gitlab-ce/tree/master/doc/api) using the Unicorn web server. It uses Sidekiq as a job queue which, in turn, uses redis as a non-persistent database backend for job information, meta data, and incoming jobs.
 
 The GitLab web app uses MySQL or PostgreSQL for persistent database information (e.g. users, permissions, issues, other meta data). GitLab stores the bare git repositories it serves in `/home/git/repositories` by default. It also keeps default branch and hook information with the bare repository.