Add the domain name of the WWW page on GitHub.

To have the par4all.org WWW site itself hosted by GitHub
Look at
https://help.github.com/articles/setting-up-a-custom-domain-with-pages
for the rationale.
Add .nojekyll to avoid Jekyll preprocessing by GitHub Pages

Since we generate the pages by ourselves, by-pass the GitHub generator
https://github.com/blog/572-bypassing-jekyll-on-github-pages
New Par4All WWW site version