We also need import staticjinja to expose make_renderer
Use the RTD theme if it's available
Whitespace tidy (mostly wrapping long lines)
Removing auto-generated header
Move git instructions to dev, and installation instructions to quickstart

Most people shouldn't need to git clone, so let's move that
to the dev documentation.

Once that's gone, there's not a lot left on the installation
pages, so let's fold that in to the quickstart instructions.
Improve the wording of the documentation
Add documentation for is_static
Merge remote-tracking branch 'upstream/master' into doctidy
Merge pull request #30 from dominicrodger/doctidy

Tidying up the documentation