Add UI team to ui CODEOWNERS (#4646)

Author: jpggvilaca

.github/CODEOWNERS

@@ -7,7 +7,7 @@
 backend/ @leoll2 @itallix @warrkan @A-Artemis
 
 # Frontend
-ui/ @jpggvilaca @camiloHimura @leoll2  # @leoll2 as backup
+ui/ @jpggvilaca @MarkRedeman @camiloHimura @pplaskie @romanowska @dwesolow
 
 # Docs
 docs/geti_tune/ @leoll2 @jpggvilaca