Current stable release documentation

[dave-kennedy]

It sounds the same as #297 but I have the version selector. There just isn't any option to view the docs for 3.0.9, which is the current stable release. I was very confused because e.g. pp.python_quoted_string is documented but doesn't exist.

Also, I'm not sure if this is a recent change, but the docs say there should be a pp.comma_separated_list when it is actually under pp.common.comma_separated_list.