* Start drafting release notes from 3.16 (Generated from GitHub)
* Reformat changes and split into sections
* Format GitHub PRs links for the docs
* Link new contributors in Markdown format
* Write up 3.16 announcement
* Bump version
* Add entry for removed Python 3.8 support
* Update release date to 28/03
* Minor rewording
* Add 3.16 announcement to the navbar and link to docs
