Automatic generation of Open Screen Protocol specification

Greetings!

Thanks to some work last evening by myself and Francois (mostly Francois)
we now auto-generate and publish the Open Screen Protocol spec from the
Bikeshed source, any time there is a commit to the *master* branch.  The
master branch is now the default branch for the repo.  It does not have
index.html and you should not include it with your PR!

This means if you want to land a patch, you should base your pull request
off the master branch.  (I went ahead and rebased the PRs in flight off of
master.) Check out the revised contribution instructions [1] for step by
step instructions.

There may be a few more tweaks to this process, but it should now be much
smoother for contributors and editors.  Thanks again Francois!

m.

[1]
https://github.com/webscreens/openscreenprotocol/blob/master/CONTRIBUTING.md