Adapt the layout of the doc readme to fit the help page.

doc/README.md

 ## The GitLab Documentation covers the following subjects
 
-+ [API](api/README.md)
-+ [Development](development/README.md)
-+ [Install](install/README.md)
-+ [Integration](integration/external-issue-tracker.md)
-+ [Legal](legal/README.md)
-+ [Markdown](markdown/markdown.md)
-+ [Permissions](permissions/permissions.md)
-+ [Public access](public_access/public_access.md)
-+ [Raketasks](raketasks/README.md)
-+ [Release](release/README.md)
-+ [Security](security/README.md)
-+ [SSH](ssh/README.md)
-+ [System hooks](system_hooks/system_hooks.md)
-+ [Update](update/README.md)
-+ [Web hooks](web_hooks/web_hooks.md)
-+ [Workflow](workflow/workflow.md)
+User documentation
+
++ [API](api/README.md) Explore how you can access GitLab via a simple and powerful API.
++ [Markdown](markdown/markdown.md) Learn what you can do with GitLab's advanced formatting system.
++ [Permissions](permissions/permissions.md) Learn what each role in a project (guest/reporter/developer/master/owner) can do.
++ [Public access](public_access/public_access.md) Learn how you can allow public and internal access to a project.
++ [SSH](ssh/README.md) Setup your ssh keys and deploy keys for secure access to your projects.
++ [Web hooks](web_hooks/web_hooks.md) Let GitLab notify you when new code has been pushed to your project.
++ [Workflow](workflow/workflow.md) Learn how to use Git and GitLab together.
+
+Administrator documentation
+
++ [Install](install/README.md) Requirements, directory structures and manual installation.
++ [Integration](integration/external-issue-tracker.md) How to integrate JIRA and Redmine.
++ [Raketasks](raketasks/README.md) Explore what GitLab has in store for you to make administration easier.
++ [System hooks](system_hooks/system_hooks.md) Let GitLab notify you when certain management tasks need to be carried out.
++ [Security](security/README.md) Learn what you can do to further secure your GitLab instance.
++ [Update](update/README.md) Update guides to upgrade your installation.
+
+Contributor documentation
+
++ [Development](development/README.md) Explains the architecture and the guidelines for shell commands.
++ [Legal](legal/README.md) Contributor license agreements.
++ [Release](release/README.md) How to make the monthly and security releases.