docs(versioning/semver): rewrite readme

[HonkingGoose]

Changes

• Rewrite the semver versioning docs:
  • One sentence per line
  • Use simpler words and phrases
  • Emphasize key info

Context

Drive by PR, not closing any issue with this.

Documentation (please check one with an [x])

• [x] I have updated the documentation, or
• [ ] No documentation update is required

How I've tested my work (please select one)

I have verified these changes via:

• [x] Code inspection only, or
• [ ] Newly added/modified unit tests, or
• [ ] No unit tests but ran on a real repository, or
• [ ] Both unit tests + ran on a real repository