- Rename docs/upgrading-spec-kit.md to docs/upgrade.md for brevity
- Update README and documentation index links to point to new upgrade guide
- Update table of contents to use shorter "Upgrade" title
- Simplify section headers in upgrade guide
- Add Getting Started section back to docs/index.md with upgrade guide link
Commit-generated-by: GitHub Copilot <github.copilot@github.com>
Signed-off-by: Ashley Childress <6563688+anchildress1@users.noreply.github.com>
