minor fix to the rubygems API documentation
Added API documentation for /api/v1/downloads/all.(json|xml|yaml)
Indicate how to add a gem owner
…our own gem' guide. The conventions are drawn from this tutorial http://tenderlovemaking.com/2009/12/18/writing-ruby-c-extensions-part-1/ http://tenderlovemaking.com/2010/12/11/writing-ruby-c-extensions-part-2/ which I've used to create a couple of C extensions that seem to work well.
…_just_updated Add documentation for /api/v1/gems/latest and /api/v1/gems/just_updated