This commit adds a small section on how to install and build Python
bindings wheels to the docs, as well as a link to it from the main readme.
Notes were added that clearly state availability of Python wheels based
on Python version and OS/architecture combinations.
For the guide to build a wheel from source, the best practice of
creating a virtual environment and activating it before build was
detailed. Also, a note on the required installation of Bazel was added,
with a link to the official docs on installation.
