Version update

Minor fix before v22 release

version update in gather.sql just before the release

Doc:More detailed explanation for ClientRead waitevent

Better english for README

Recommendations on AUTOVACUUM settings at table level

Fix: Column index changed as part of new columns to table

parameters: checkpoint_timeout and hot_standby_feedback checks

multiple changes merting with the main gather_report.sql

few more cleanups before finalization of v14