Update release instruction. (#1471)
Update release instruction. (#1471)

* Update release instruction.

* Update RELEASING.md

Co-authored-by: Matt Moore <866b498749d560dfd4b9805e44d1fa0b8bc948c7@vmware.com>

* Add new step to update doc.

* Update RELEASING.md

Co-authored-by: Matt Moore <866b498749d560dfd4b9805e44d1fa0b8bc948c7@vmware.com>

* Update RELEASING.md

Co-authored-by: Matt Moore <866b498749d560dfd4b9805e44d1fa0b8bc948c7@vmware.com>

Co-authored-by: Matt Moore <866b498749d560dfd4b9805e44d1fa0b8bc948c7@vmware.com>
knative/pkg,knative/pkg