Update CODEOWNERS

Including myself in .script for when we need to update validations

CODEOWNERS

@@ -7,7 +7,7 @@
 
 # This is copied from here: https://help.github.com/en/github/creating-cloning-and-archiving-repositories/about-code-owners
 
-/.script/ @oshvartz @Amitbergman @ShaniFelig @laithhisham
+/.script/ @oshvartz @Amitbergman @ShaniFelig @laithhisham @shainw
 /ASIM/ @oshezaf @YaronFruchtmann
 /DataConnectors/ @NoamLandress @shschwar @ashishsyal @preetikr @haim-na
 /Detections/ @timbMSFT @juliango2100 @oshezaf @aprakash13 @ashwin-patil @petebryan @shainw @thmcelro