Add codeowners

Author: AndyRae

.github/CODEOWNERS

@@ -0,0 +1,6 @@
+# This is a CODEOWNERS file. It defines who is responsible for different parts of the codebase.
+# See https://docs.github.com/en/repositories/managing-your-repositorys-settings-and-features/customizing-your-repository/about-code-owners
+
+# These owners will be the default owners for everything in the repo.
+* @andyrae
+* @AndrewThien