docs: Update community member listings (#3038)

Co-authored-by: otelbot <[email protected]>
Co-authored-by: Utkarsh Umesan Pillai <[email protected]>
Co-authored-by: Cijo Thomas <[email protected]>

Author: 4 people

README.md

@@ -186,13 +186,17 @@ you're more than welcome to participate!
 * [Utkarsh Umesan Pillai](https://github.com/utpilla), Microsoft
 * [Zhongyang Wu](https://github.com/TommyCpp)
 
+For more information about the maintainer role, see the [community repository](https://github.com/open-telemetry/community/blob/main/guides/contributor/membership.md#maintainer).
+
 ### Approvers
 
 * [Anton Grübel](https://github.com/gruebel), Baz
 * [Björn Antonsson](https://github.com/bantonsson), Datadog
 * [Shaun Cox](https://github.com/shaun-cox), Microsoft
 * [Scott Gerring](https://github.com/scottgerring), Datadog
 
+For more information about the approver role, see the [community repository](https://github.com/open-telemetry/community/blob/main/guides/contributor/membership.md#approver).
+
 ### Emeritus
 
 * [Dirkjan Ochtman](https://github.com/djc)
@@ -201,6 +205,8 @@ you're more than welcome to participate!
 * [Isobel Redelmeier](https://github.com/iredelmeier)
 * [Mike Goldsmith](https://github.com/MikeGoldsmith)
 
+For more information about the emeritus role, see the [community repository](https://github.com/open-telemetry/community/blob/main/guides/contributor/membership.md#emeritus-maintainerapprovertriager).
+
 ### Thanks to all the people who have contributed
 
 [![contributors](https://contributors-img.web.app/image?repo=open-telemetry/opentelemetry-rust)](https://github.com/open-telemetry/opentelemetry-rust/graphs/contributors)