Updating practices for maintainers (#1611)

Signed-off-by: Peter Nied <petern@amazon.com>

MAINTAINERS.md

@@ -1,3 +1,7 @@
+- [OpenSearch Security Maintainers](#opensearch-security-maintainers)
+  - [Maintainers](#maintainers)
+    - [Updating Practices](#updating-practices)
+
 # OpenSearch Security Maintainers
 
 ## Maintainers
@@ -6,4 +10,7 @@
 | Chang Liu        | [cliu123](https://github.com/cliu123)                 | Amazon      |
 | Darshit Chanpura | [DarshitChanpura](https://github.com/DarshitChanpura) | Amazon      |
 | Dave Lago        | [davidlago](https://github.com/davidlago)             | Amazon      |
-| Peter Nied       | [peternied](https://github.com/peternied)             | Amazon      |
+| Peter Nied       | [peternied](https://github.com/peternied)             | Amazon      |
+
+### Updating Practices
+To ensure common practices as maintainers, all practices are expected to be documented here or enforced through github actions.  There should be no expectations beyond what is documented in the repo [CONTRIBUTING.md](./CONTRIBUTING.md) and OpenSearch-Project [CONTRIBUTING.md](https://github.com/opensearch-project/.github/blob/main/CONTRIBUTING.md).  To modify an existing processes or create a new one, make a pull request on this MAINTAINERS.md for review and merge it after all maintainers approve of it.