chore: add maintainers file

Author: Joel Lee

Diff for: supabase/lib/MAINTAINERS.md

@@ -0,0 +1,14 @@
+This page lists all active maintainers of this repository. If you were a maintainer and would like to add your name to the Emeritus list, please send us a PR.
+
+See CONTRIBUTING.md for general contribution guidelines.
+
+# Maintainers (in alphabetical order)
+
+- [anand2312](https://github.com/anand2312)
+- [dreinon](https://github.com/dreinon)
+- [J0](https://github.com/J0)
+- [leynier](https://github.com/leynier)
+
+# Emeritus Maintainers (in alphabetical order)
+
+- [fedden](https://github.com/fedden)