message: Update README for Python.
diff: -# Tink for Python
  +# Tink
  -NOTE: This is still under active development and the API might change until the
  -official release.
  +Using crypto in your application shouldn't have to feel like juggling chainsaws
  +in the dark. Tink is a crypto library written by a group of cryptographers and
  +security engineers at Google. It was born out of our extensive experience
  +working with Google's product teams, fixing weaknesses in implementations, and
  +providing simple APIs that can be used safely without needing a crypto
  +background.
  +
  +Tink provides secure APIs that are easy to use correctly and hard(er) to misuse.
  +It reduces common crypto pitfalls with user-centered design, careful
  +implementation and code reviews, and extensive testing. At Google, Tink is
  +already being used to secure data of many products such as AdMob, Google Pay,
  +Google Assistant, Firebase, the Android Search App, etc.
  ## Documentation
  -For an overview of using the Tink Python implementation, see the [Python
  -HOW-TO](../docs/PYTHON-HOWTO.md).
  +For an overview of using Tink in Python, see the
  +[Python HOW-TO](../docs/PYTHON-HOWTO.md).
  In addition, there are illustrative [examples of using Tink
  Python](https://github.com/google/tink/tree/master/examples/python/) which can
  