Add API docs in global nav

Now that we have a functional global nav, let's add the API docs!

There's only one that I didn't add api/deploy_key_multiple_projects.md, which should ideally be merged with api/deploy_keys.md.

http://api-global-nav.178.62.207.141.xip.io/ce/api/README.html

Todos

• Add versions to EE endpoints