make documentation available online

[jellegerbrandy]

eventually, we will want the documentation on http://read-the-docs.readthedocs.org/en/latest/webhooks.html

a quick solution could be https://rawgit.com/, but the repository needs to be public for it to work.

[jellegerbrandy]

http://backfeed-restapi.readthedocs.org/en/latest/