Merge pull request #756 from microsoft/ag-codeowners

chore: Add CODEOWNERS file with default owners

Author: Roopan-Microsoft

.github/CODEOWNERS

@@ -0,0 +1,5 @@
+# Lines starting with '#' are comments.
+# Each line is a file pattern followed by one or more owners.
+
+# These owners will be the default owners for everything in the repo.
+* @Avijit-Microsoft @Roopan-Microsoft @Prajwal-Microsoft @aniaroramsft @Vinay-Microsoft @malrose07 @toherman-msft @nchandhi