Announcing Vitess 13

Vitess 13 is now generally available, with improvements made in query serving and cluster management, including enhanced compatibility and better support for multi-column vindexes. The release also brings significant enhancements to the VTOrc component, allowing for more robust user-initiated emergency failovers and improved GTID detection. Additionally, versioned documentation is now available on the website, making it easier for users to find relevant information for their specific Vitess release.