Updated MAINTAINERS.md to match recommended opensearch-project format. (#589)

Signed-off-by: dblock <[email protected]>

Signed-off-by: dblock <[email protected]>

Author: dblock

MAINTAINERS.md

@@ -1,6 +1,11 @@
-## Maintainers
-| Maintainer             | GitHub ID                                         | Affiliation |
-|------------------------|---------------------------------------------------|-------------|
-| Anantha Krishna Bhatta | [akbhatta](https://github.com/akbhatta)           | Amazon      |
-| Joshua Li              | [joshuali925](https://github.com/joshuali925)     | Amazon      |
-| Zhongnan Su            | [zhongnansu](https://github.com/zhongnansu)       | Amazon      |
+## Overview
+
+This document contains a list of maintainers in this repo. See [opensearch-project/.github/RESPONSIBILITIES.md](https://github.com/opensearch-project/.github/blob/main/RESPONSIBILITIES.md#maintainer-responsibilities) that explains what the role of maintainer means, what maintainers do in this and other repos, and how they should be doing it. If you're interested in contributing, and becoming a maintainer, see [CONTRIBUTING](CONTRIBUTING.md).
+
+## Current Maintainers
+
+| Maintainer             | GitHub ID                                     | Affiliation |
+| ---------------------- | --------------------------------------------- | ----------- |
+| Anantha Krishna Bhatta | [akbhatta](https://github.com/akbhatta)       | Amazon      |
+| Joshua Li              | [joshuali925](https://github.com/joshuali925) | Amazon      |
+| Zhongnan Su            | [zhongnansu](https://github.com/zhongnansu)   | Amazon      |