Add docs, project info documents, update README

* bump version to 1.2.2
* use Python 2/3 compatible imports and string formatting
* include vendored theme
Rename sample package to pypkg

* version bump to 1.2.3
* rebase onto latest upstream changes
Fix docs code-blocks and mention bdist_wheel
Add details to docs

* Add prose description to docs index page
* Add checklist items to README
* Separate development and docs requirements