Firefox 85 release notes (January 26)

[chrisdavidmills]

Acceptance criteria

1. • Firefox 85 release notes are updated with all DDN and DDC bugs.
2. • Experimental Features page is updated.
3. • platform-status is updated accordingly.
4. • Hacks blogpost written about Fx 85 new features
5. • Hacks blog post shared with Melissa, Mike Conca, Caitlin Neiman, Asa Dotzler, Jen Boscacci, and Tyler Ahn.
6. • Links to the Fx hacks blog post is added to the rel notes on MDN.
7. • A new version of the mdn-data npm package is released, if changes were made in the last sprint.
8. • The BCD browser json files mark Firefox 85 as the current release

Estimated total: 3 days work.