Github Pages support

[jblomo]

Repositories with a gh-pages branch will have a website hosted by Github with the contents of that branch. We can use Github Pages to host the example slideshow. This change adds support for the gh-pages branch by:

• moving the example.org file to index.org
• changing the submodules to the git protocol

After applying this change, add a gh-pages branch by running git symbolic-ref refs/heads/gh-pages refs/heads/master then git push --all. This will make the gh-pages branch track master. To keep the Github Pages site up-to-date, you will need to run git push --all after committing to master.

Demo at http://jblomo.github.com/org-html-slideshow/

[stuartsierra]

Thank you for the contribution but I do not see sufficient need for this addition.