Create CODEOWNERS file (#321)

* Create CODEOWNERS

Add global code owners

* Add Document Owners

.github/CODEOWNERS

@@ -0,0 +1,6 @@
+* @rrawther @AryanSalmanpour
+
+# Documentation files
+docs/* @ROCm/rocm-documentation
+*.md @ROCm/rocm-documentation
+*.rst @ROCm/rocm-documentation