[docs] [issue20090] slight ambiguity in README.txt instructions for building docs

[Zachary Ware]

Zachary Ware added the comment:

For 2.7 and 3.3, the error message just needs to be fixed (s/3.0/3.x/); it lives in the sphinx-build.py script somewhere in Doc/.  For default, though, since we now rely on an installed version of Sphinx rather than a checked out version, the whole version check needs to be removed and just let Sphinx deal with version checking on its own.

----------
nosy: +zach.ware
versions: +Python 2.7, Python 3.3

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue20090>
_______________________________________