☂ ATS 10 Documentation

Added documentation to Upgrading if there is a change in the feature OR add documentation to What's New if there is a new feature.

1. Add your name after the PR below that you will be documenting, to assign it to yourself.
2. In the comment of the documentation PR add the number of the PR you are documenting (e.g. `#10796`). This will automatically link the original PR with the documentation PR.
3. Check the box after the PR has been submitted to GitHub.
4. Label the original incompatible PR with "Release Doc Done", so we know which incompatible changes have been documented.

For Reference: [Search query for incompatible PRs](https://github.com/apache/trafficserver/pulls?q=is%3Apr+is%3Aclosed+milestone%3A10.0.0+sort%3Acreated-asc+label%3AIncompatible)

- [x] #6602 (@duke8253)
- [x] #7302 (@bneradt)
- [x] #7335 (@bneradt)
- [x] #7478 (@brbzull0)
- [x] #7547 (@bneradt)
- [x] #7587 (@moonchen)
- [x] #7693 (@moonchen)
- [x] #7756 (@moonchen)
- [x] #7901 (@maskit)
- [x] #8066 (@maskit)
- [x] #8077 (@cmcfarlen)
- [x] #8463 (@cmcfarlen)
- [x] #8591 (@cmcfarlen)
- [x] #8633 (@brbzull0)
- [x] #8719 (@cmcfarlen)
- [x] #8804 (@maskit)
- [x] #8891 (@cmcfarlen)
- [x] #8893 (@cmcfarlen)
- [x] #9019 (@maskit)
- [x] #9138 (@maskit)
- [x] #9257 (@bryancall)
- [x] #9258 (@maskit)
- [x] #9264 (@brbzull0)
- [x] #9273 (@maskit)
- [x] #9334 (@cmcfarlen)
- [x] #9388 (@cmcfarlen)
- [x] #9465 (@maskit)
- [x] #9509 (@maskit)
- [x] #9582 (@bneradt)
- [x] #9631 (@bneradt)
- [x] #9667 (@maskit)
- [x] #9736 (@masaori335)
- [x] #9799 (@cmcfarlen)
- [x] #9818 (@maskit)
- [ ] #9915
- [ ] #9923
- [ ] #10007 (@bryancall)
- [x] #10111 (@maskit)
- [ ] #10303
- [x] #10368 (@cmcfarlen)
- [x] #10441 (@cmcfarlen)
- [x] #10472 (@cmcfarlen)
- [x] #10549 (@cmcfarlen)
- [x] #10683 (@ywkaras)
- [x] #10688 (@cmcfarlen)
- [x] #10708 (@cmcfarlen)
- [x] #10710 (@cmcfarlen)
- [x] #10714 (@cmcfarlen)
- [x] #10794 (@cmcfarlen)
- [x] #10796 (@bryancall)
- [x] #10910 (@bryancall)
- [x] #11033 (@bryancall)
- [x] #11045 (@bryancall)
- [x] #11171 (@bryancall)
- [x] #11344 (@maskit)
- [x] #11432 (@maskit)
- [x] #11519 (@maskit)
- [x] #11569 (@maskit)
- [x] #11570 (@maskit)
- [x] #11571 (@maskit)
- [x] #11572 (@maskit)
- [x] #11579 (@maskit)
- [x] #11586 (@maskit)
- [x] #11587 (@maskit)
- [x] #11624 (@maskit)

[Search query for New Feature PRs](https://github.com/apache/trafficserver/pulls?q=is%3Apr+label%3A%22New+Feature%22+is%3Aclosed+milestone%3A10.0.0+-label%3AIncompatible)

- [x] #11192 (@sharkleash)
- [ ] #10701
- [x] #10627 (@maskit)
- [x] ~#10563~ Available since 9.2.4
- [x] #10559 (@brbzull0)
- [x] #10444 (@brbzull0)
- [x] #10306 (@maskit)
- [x] #10163 (@cmcfarlen)
- [ ] #9988
- [ ] #9987
- [x] #9728 (@cmcfarlen)
- [x] #9616 (@maskit)
- [x] #9594 (@brbzull0)
- [x] #9574 (@cmcfarlen)
- [x] #9501 (@cmcfarlen)
- [x] #9423 (@cmcfarlen)
- [x] #9379 (@maskit)
- [x] #9366 (@maskit)
- [x] #9271 (@maskit)
- [x] #9263 (@cmcfarlen)
- [x] #9249 (@maskit)
- [x] #9232 (@maskit)
- [x] #9228 (@cmcfarlen)
- [x] #9085 (@maskit)
- [x] #8953 (@brbzull0)
- [x] #8630 (@brbzull0)