[docs] Document download links give 404 - Not Found

[Peter Jardine]

Trying to download Python docs. All links tried for v2.7 or v3 downloads 
give 404 Not Found - nginx

Tried:

from: https://docs.python.org/2.7/download.html

https://docs.python.org/2.7/archives/python-2.7.14-docs-pdf-a4.zip
https://docs.python.org/2.7/archives/python-2.7.14-docs-pdf-a4.tar.bz2
https://docs.python.org/2.7/archives/python-2.7.14-docs-html.zip
https://docs.python.org/2.7/archives/python-2.7.14-docs-html.tar.bz2


from: https://docs.python.org/3/download.html

https://docs.python.org/3/archives/python-3.6.2-docs-pdf-a4.zip
https://docs.python.org/3/archives/python-3.6.2-docs-pdf-a4.tar.bz2
https://docs.python.org/3/archives/python-3.6.2-docs-html.zip
https://docs.python.org/3/archives/python-3.6.2-docs-html.tar.bz2


Links for v3.5 worked ok.

Regards,
Peter J