Squashed 'docs/_esnet/' content from commit c02bf57

git-subtree-dir: docs/_esnet
git-subtree-split: c02bf57d43dbfcd7c727cdd17c54f0a480279f9a
Merge commit 'f70fd5bc614e61f47bc46dda40f8b42e4fd55e98' as 'docs/_esnet'
add favicon and link to github page
translate .hgignore to .gitignore; add symlink in docs/_static