Activate Github Pages on demos

If you add an index.html file to the root of the Github demos page, and activate Pages in settings of the repository you can host many demos automatically, so it’s faster to test the demos, at least the ones that don’t need setup.
I forked the repository and did it in my copy if you want to check, for example here, I added files to the proyects which did not have it, with a link to the hosted github page, those links work once you activate Github pages and add the index.html to the root (the index.html can be empty, but it’s needed by Github otherwise it won’t work).