Preapre doc for Jekyll
Move documentation to src/
Squashed 'doc/old/' content from commit 9998c28

git-subtree-dir: doc/old
git-subtree-split: 9998c289b6e2456c967a71a7ef2d3cfaf73e85a5
Merge commit '0b091d96c910e8b4151f9c5ba2ed0420c1fccfdd' as 'doc/old'
Move files from old ghpages to new organization
Update layout to relative path for stylesheets
Replace HTML tags by markdown-only
Use torchonly + README.md as index