addons(postgresql): add pg_repack

Author: aurrelhebert

content/doc/addons/postgresql.md

@@ -141,6 +141,7 @@ Extension   | Description
 pg_cron     | Job scheduler for PostgreSQL
 pg_ivm      | Incremental view maintenance for PostgreSQL
 pg_net      | Enables asynchronous (non-blocking) HTTP/HTTPS requests with SQL
+pg_repack   | Reorganize tables in PostgreSQL databases with minimal locks
 pgaudit     | Provides detailed session and/or object audit logging via the standard PostgreSQL logging facility
 pgsql-http  | HTTP client for PostgreSQL
 pgtap       | Unit testing for PostgreSQL