Docs: V5 migration

[lukegalbraithrussell]

Summary

Docs for the migration to v5

Requirements

• I've read and understood the Contributing Guidelines and have done my best effort to follow them.
• I've read and agree to the Code of Conduct.

[changeset-bot]

⚠️ No Changeset found

Latest commit: 1975fbd

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 94.29%. Comparing base (6779cf7) to head (1975fbd).
⚠️ Report is 13 commits behind head on v5.

Additional details and impacted files

@@            Coverage Diff             @@
##               v5    #2949      +/-   ##
==========================================
- Coverage   94.38%   94.29%   -0.10%     
==========================================
  Files          44       43       -1     
  Lines        7857     7323     -534     
  Branches      699      677      -22     
==========================================
- Hits         7416     6905     -511     
+ Misses        435      410      -25     
- Partials        6        8       +2     

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