Changelog:

 * Changed storage for vector from extended to external
 * Added support for parallel index builds for HNSW
 * Added validation for GUC parameters
 * Improved performance of HNSW
 * Reduced memory usage for HNSW index builds
 * Reduced WAL generation for HNSW index builds
 * Fixed error with logical replication
 * Fixed invalid memory alloc request size error with HNSW index builds
 * Moved Docker image to pgvector org
 * Added Docker tags for each supported version of Postgres
 * Dropped support for Postgres 11