CODEOWNERS: add osm-docs-approvers (openservicemesh#315)

Adds osm-docs-approvers as a code owner.

Signed-off-by: Shashank Ram <[email protected]>

Author: shashankram

CODEOWNERS

@@ -1,4 +1,4 @@
 # ref: https://docs.github.com/en/github/creating-cloning-and-archiving-repositories/about-code-owners
 # CODEOWNERS include members of the osm-approvers team - https://github.com/orgs/openservicemesh/teams/osm-approvers/members
 # CODEOWNERS include members of the osm-www team - https://github.com/orgs/openservicemesh/teams/osm-www/members
-* @openservicemesh/osm-approvers @openservicemesh/osm-www
+* @openservicemesh/osm-approvers @openservicemesh/osm-docs-approvers @openservicemesh/osm-www