MAINTAINERS: update guidelines

Update guidelines regarding updates to maintainers in the MAINTAINER
file.

Signed-off-by: Anas Nashif <[email protected]>

Author: nashif

doc/contribute/project_roles.rst

@@ -194,7 +194,17 @@ Generic guidelines for deciding and filling in the Maintainers' list
 
   * Re-assigned by original assignee (see “Assignee” slide)
 
-* Updates to the MAINTAINERS file should be in a standalone PRs
+* In general, updates to the MAINTAINERS file should be
+  in a standalone commit alongside other changes introducing new files and
+  directories to the tree.
+* Major changes to the file, including the addition of new areas with new maintainers
+  should come in as standalone pull-requests and require TSC review.
+* If additional review by the TSC is required, the maintainers of the file
+  should send the requested changes to the TSC and give members of the TSC two
+  (2) days to object to any of the changes to maintainership of areas or the
+  addition of new maintainers or areas.
+* Path, collaborator and name changes do not require a review by the TSC.
+* Addition of new areas without a maintainer do not require review by the TSC.
 * The MAINTAINERS file itself shall have a maintainer
 * Architectures, core components, sub-systems, samples, tests