Add contributing guide, MCP server link and dev sync workflow - #22

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/attest-build-provenance/predicate@1176ef556905f349f669722abf30bce1a6e16e01, actions/attest@ce27ba3b4a9a139d9a20a4a07d69fabb52f1e5bc, actions/checkout@v4, actions/upload-artifact@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/