Add CODEOWNERS file

Author: shahmishal

CODEOWNERS

@@ -0,0 +1,14 @@
+#
+# This source file is part of the Swift.org open source project
+#
+# Copyright (c) 2024 Apple Inc. and the Swift project authors
+# Licensed under Apache License v2.0 with Runtime Library Exception
+#
+# See https://swift.org/LICENSE.txt for license information
+# See https://swift.org/CONTRIBUTORS.txt for Swift project authors
+#
+
+* @ahoppen @allevato @bnbarham @shawnhyam
+
+.github/ @shahmishal
+.swiftci/ @shahmishal