Add Doc team to CODEOWNERS file

Signed-off-by: David Galiffi <David.Galiffi@amd.com>
Change-Id: Iad8eea0645b63bddb835ed22080facc7d25c1bc0

.github/CODEOWNERS

@@ -1 +1,5 @@
 * @dmitrii-galantsev @bill-shuzhou-liu
+
+docs/* @ROCm/rocm-documentation
+*.md @ROCm/rocm-documentation
+*.rst @ROCm/rocm-documentation