docs(backport): Update citations and README

[matthewfeickert]

Description

Backport citations

• Backport:
  • PR https://github.com/scikit-hep/pyhf/pull/2375
  • PR https://github.com/scikit-hep/pyhf/pull/2392
  • PR https://github.com/scikit-hep/pyhf/pull/2393
  • PR https://github.com/scikit-hep/pyhf/pull/2394
  • PR https://github.com/scikit-hep/pyhf/pull/2406
  • PR https://github.com/scikit-hep/pyhf/pull/2407
  • PR https://github.com/scikit-hep/pyhf/pull/2408
  • PR https://github.com/scikit-hep/pyhf/pull/2415
  • PR https://github.com/scikit-hep/pyhf/pull/2416
  • PR https://github.com/scikit-hep/pyhf/pull/2417
  • PR https://github.com/scikit-hep/pyhf/pull/2418

Checklist Before Requesting Reviewer

• [x] Tests are passing
• [x] "WIP" removed from the title of the pull request
• [x] Selected an Assignee for the PR to be responsible for the log summary

Before Merging

For the PR Assignees:

• [x] Summarize commit messages into a comprehensive review of the PR

* Backport:
   - PR https://github.com/scikit-hep/pyhf/pull/2375
   - PR https://github.com/scikit-hep/pyhf/pull/2392
   - PR https://github.com/scikit-hep/pyhf/pull/2393
   - PR https://github.com/scikit-hep/pyhf/pull/2394
   - PR https://github.com/scikit-hep/pyhf/pull/2406
   - PR https://github.com/scikit-hep/pyhf/pull/2407
   - PR https://github.com/scikit-hep/pyhf/pull/2408
   - PR https://github.com/scikit-hep/pyhf/pull/2415
   - PR https://github.com/scikit-hep/pyhf/pull/2416
   - PR https://github.com/scikit-hep/pyhf/pull/2417
   - PR https://github.com/scikit-hep/pyhf/pull/2418