docs: adds MAINTAINERS.md (#1380)

**Description**

This adds MAINTAINERS.md to clarify who has the write permission to the
repository. This will also help contributors know who they need to talk
to when they have questions, etc.

---------

Signed-off-by: Takeshi Yoneda <[email protected]>

Author: mathetake

CONTRIBUTING.md

@@ -106,3 +106,4 @@ make sure that these automated checks pass after you open a PR by following the
   as commit message by default. Maintainers may request contributors to
   edit the pull request title and description to ensure that it remains descriptive as a
   commit message. Alternatively, maintainers may change the commit message directly at the time of merge.
+- If you have any questions during the review, please feel free to ask the maintainers listed in [MAINTAINERS.md](./MAINTAINERS.md).

MAINTAINERS.md

@@ -0,0 +1,22 @@
+## Maintainers
+
+The following people are responsible for maintaining the Envoy AI Gateway project.
+Please reach out to them for any questions, issues, or contributions related to the project.
+
+- Takeshi Yoneda ([@mathetake](https://github.com/mathetake))
+  - Area: Everything
+  - [Envoy Proxy](https://github.com/envoyproxy/envoy) Maintainer
+- Dan Sun ([@yuzisun](https://github.com/yuzisun))
+  - Area: Everything, focusing on enterprise integration & core LLM features.
+  - [KServe](https://github.com/kserve/kserve) Maintainer
+- Erica Hughberg ([@missBerg](https://github.com/missBerg))
+  - Area: Documentation, WebSite, Community
+- Aaron Choo ([@aabchoo](https://github.com/aabchoo))
+  - Area: Control Plane, Security Policy, Testing
+- Yao Weng ([@wengyao04](https://github.com/wengyao04))
+  - Area: Control Plane, Testing
+- Xunzhuo (Bit) Liu ([@Xunzhuo](https://github.com/Xunzhuo))
+  - Area: Control Plane, Inference Pool & Gateway API Inference Extension
+  - [Envoy Gateway](https://github.com/envoyproxy/gateway) maintainer
+- Ignasi Barrera ([@nacx](https://github.com/nacx))
+  - Area: MCP, aigw CLI (standalone mode)