add admin file

Signed-off-by: Derek Ho <[email protected]>

ADMINS.md

@@ -0,0 +1,9 @@
+## Admins
+
+| Admin              | GitHub ID                               | Affiliation |
+| ------------------ | --------------------------------------- | ----------- |
+| Charlotte Henkle   | [CEHENKLE](https://github.com/CEHENKLE) | Amazon      |
+| Daniel Doubrovkine | [dblock](https://github.com/dblock)     | Amazon      |
+| Henri Yandell      | [hyandell](https://github.com/hyandell) | Amazon      |
+
+[This document](https://github.com/opensearch-project/.github/blob/main/ADMINS.md) explains what admins do in this repo. and how they should be doing it. If you're interested in becoming a maintainer, see [MAINTAINERS](MAINTAINERS.md). If you're interested in contributing, see [CONTRIBUTING](CONTRIBUTING.md).