Add config for GitHub Pages so that we can use it as a project blog.
* _config.yml is jekyll configuration
* index.md contains description and title for the blog main page.
* Any files matching "_posts/YYYY-MM-DD-TITLE.md" are considered posts
The Github Pages configuration only allows "/" or "/docs/" as the Jekyll
root directory: The clutter in docs/ is annoying but otherwise this is a
very easy setup.
Signed-off-by: Jussi Kukkonen <jkukkonen@vmware.com>