Fix comments from review & trim trailing spaces

proposals/1929-admin-contact.md

@@ -44,10 +44,10 @@ proposal are `m.role.admin` and `m.role.security`.
  - `m.role.admin` is a catch-all user for any queries.
  - `m.role.security` is intended for sensitive requests
 
-Implementors may use custom values for role for other purposes, but it's suggested
-that the value be namespaced to prevent collisions. A value for `role` MUST be specified.
+A value for `role` MUST be specified. Custom values are permitted using the
+[common namespaced identifier format](https://spec.matrix.org/v1.8/appendices/#common-namespaced-identifier-grammar).
 
-`support_page` is an optional property to specify a affiliated page of the homserver to give users help
+`support_page` is an optional property to specify an affiliated page of the homeserver to give users help
 specific to the homeserver, like extra login/registration steps.
 
 At least one valid key should be provided. This means `contacts` should have at least one entry, or the `support_page` should be defined. An empty object is not considered valid, however both `contacts `and `support_page` may be specified together.