[docs] Reduce Github pull request rate (issue 27680)

[ghost.adh at runbox.com]

https://bugs.python.org/review/27680/diff/18057/README.md
File README.md (right):

https://bugs.python.org/review/27680/diff/18057/README.md#newcode16
README.md:16: at https://hg.python.org/, updated daily as a service to
those who are already using
perhaps link to https://hg.python.org/cpython ?

https://bugs.python.org/review/27680/diff/18057/README.md#newcode23
README.md:23: explains all you need you know to join the Python
developers. If you are
all you need to know

https://bugs.python.org/review/27680/diff/18057/README.md#newcode24
README.md:24: interested in contributring then we especially recommend
that you read
contributing

https://bugs.python.org/review/27680/diff/18057/README.md#newcode27
README.md:27: Thanks for taking time to visit the Python repository, and
for yout interest in Python.
your

https://bugs.python.org/review/27680/