Update docs links to tzdata.python.org (#125)

Author: StanFromIreland

README.rst

@@ -9,4 +9,4 @@ location), as a part of `PEP 615 <https://www.python.org/dev/peps/pep-0615/>`_
 This repository generates a ``pip``-installable package, published on PyPI as
 `tzdata <https://pypi.org/project/tzdata>`_.
 
-For more information, see `the documentation <https://tzdata.readthedocs.io>`_.
+For more information, see `the documentation <https://tzdata.python.org>`_.

setup.cfg

@@ -19,7 +19,7 @@ classifiers =
 project_urls =
     Bug Reports = https://github.com/python/tzdata/issues
     Source = https://github.com/python/tzdata
-    Documentation = https://tzdata.readthedocs.io
+    Documentation = https://tzdata.python.org
 
 [options]
 packages = tzdata