Adds a docs pipeline so each release has a version-bound Markdown
document (docs/releases/vX.Y.Z.md) rendered publicly in the app:
- sync-release-docs.mjs copies docs/releases/*.md into the toolrate
public dir and generates index.json before every dev/build
- /docs lists all releases; /docs/:version renders the sanitized
Markdown (marked + DOMPurify, typography styles)
- template + workflow documented in docs/README.md
- current release (v0.6.0) documented as the first entry