[docs] Confusing default redirects

[Dražen Lučanin]

Dear Sir/Madam,

When I open http://docs.python.org/ it redirects me to http://docs.python.org/3/

When I open http://docs.python.org/library/ it redirects me to
http://docs.python.org/2/library/

Expected - all "versionless" URLs should redirect to the same (current
stable and recommended) version of Python.

Regards,
Dražen Lučanin