Fix CODEOWNERS syntax

.github/CODEOWNERS

@@ -1,8 +1,3 @@
-# These owners will be the default owners for everything in
-# the repo. Unless a later match takes precedence, 
-# they will be requested for review when someone opens a 
-# pull request.
+# This codebase has shared ownership and responsibility.
 
-*       @hashicorp/tf-editor-experience-engineers
-*       @hashicorp/terraform-devex
-*       @hashicorp/terraform-core
+* @hashicorp/terraform-core @hashicorp/terraform-devex @hashicorp/tf-editor-experience-engineers