Add Arhell to sig-docs-uk-owners

Author: Arhell

OWNERS_ALIASES

@@ -233,6 +233,7 @@ aliases:
     - kpucynski
   sig-docs-uk-owners: # Admins for Ukrainian content
     - anastyakulyk
+    - Arhell
     - butuzov
     - MaxymVlasov
   sig-docs-uk-reviews: # PR reviews for Ukrainian content