Add empty gh-pages branch

[chohner]

Please create empty gh-pages brach (git checkout --orphan gh-pages) to host the documentation (corresponding PR is ready on my end). Will then look like this.

[chohner]

Sorry, forgot that you have to clean the branch before commiting it. Could you please delete the current gh-pages branch and then do the following:

git checkout --orphan gh-pages
git rm -rf .
git commit --allow-empty -m "init gh-pages docu"
git push origin gh-pages

That should result in an empty gh-branch which you can fill with the documentation.

[chohner]

Alternatively, you can just merge this humongous PR https://github.com/m-rest/rt-wdf/pull/10