docs: add release-to-production workflow to CONTRIBUTING.md

[anurag629]

Adds a Releasing to Production section to CONTRIBUTING.md explaining:

• When and how to add changesets (pnpm changeset)
• The dev → production merge flow
• How the Release workflow + Changesets action handles versioning and npm publishing
• That website deploys automatically via Vercel
• Note for contributors vs maintainers

[vercel]

@anurag629 is attempting to deploy a commit to the CODERCOPS Team on Vercel.

A member of the Team first needs to authorize it.