dumpling: Update tidb-mem-quota-query configuration instructions (#4942)
dumpling: Update tidb-mem-quota-query configuration instructions (#4942)

* Update dumpling-overview.md

* Update dumpling-overview.md

* Update dumpling-overview.md

Co-authored-by: TomShawn <3d0966147538bc5ab020e8dffa2c0b746f9728a6@users.noreply.github.com>
pingcap/docs,pingcap/docs,pingcap/docs