Add owner for CDN (#27204)

Co-authored-by: Chenglong Liu <chengll@microsoft.com>

Author: ChenglongLiu

CODEOWNERS

@@ -59,7 +59,7 @@
 /specification/billing/ @wilcobmsft @asarkar84
 
 # PRLabel: %Network - CDN
-/specification/cdn/ @jorinmejia @yunhemsft @jessicl-ms @rrahulms @t-bzhan
+/specification/cdn/ @jorinmejia @yunhemsft @jessicl-ms @rrahulms @t-bzhan @ChenglongLiu
 
 # PRLabel: %Cognitive Services
 /specification/cognitiveservices/ @felixwa @yangyuan