README: document PR raising process

Signed-off-by: Laura Flores <[email protected]>

README.md

@@ -187,6 +187,13 @@ _Note:_ Shortcode arguments are type-/space-sensitive, so should should include
 
 We now have a single source of truth for the YouTube embed code making it easy to maintain and easy to reuse with a simple, clean interface.
 
+## Proposing a Change
+
+Anyone may raise a pull request to suggest a change. However, only those belonging to the [GitHub Ceph organization](https://github.com/ceph)
+can trigger the "Compiling Site" check, which is required for the pull request to merge. Those who do not belong to the GitHub Ceph
+organization should ask a member of the organization to approve their change, then raise another pull request with the suggested change to
+trigger the "Compiling Site" check.
+
 ## :warning: Something wrong with ceph.io website?
 
-Report any website issues you experience by email to **Mike Perez** <[email protected]>, *Ceph Community Manager*. Please include a brief description of the problem and a link that led to it. 
+Report any website issues you experience by email to **Mike Perez** <[email protected]>, *Ceph Community Manager*. Please include a brief description of the problem and a link that led to it.