docs: Update named edx-platform maintainers.

Currently this group contains @feanil and @kdmccormick though more
maintainers can be added in the future.  While 2u-arch-bom has done a
great job thus far maintaining this repo, they don't currently have the
capacity to help drive maintenance of edx-platform moving forward.
This update should help make it easier to get help and coordinate work
on edx-platform moving forward.

catalog-info.yaml

@@ -11,6 +11,6 @@ metadata:
       title: "Documentation"
       icon: "Web"
 spec:
-  owner: group:2u-arch-bom
+  owner: group:wg-maintenance-edx-platform
   type: 'service'
   lifecycle: 'production'