Update README.rst
Update README.rst
Revert "Update README.rst"

This reverts commit b135eb7eadde707dc10e5867e982bca57e07b584.
Revert "Update README.rst"

This reverts commit 59b4fa522b2f0ade686f50f1daf2c2bfaa6e6dc8.
Add some basic instructions on building the docs.