Update CODEOWNERS

Add hellohuanlin to iOS part of pigeon
diff --git a/CODEOWNERS b/CODEOWNERS
index 7ccddb1..305974b 100644
--- a/CODEOWNERS
+++ b/CODEOWNERS
@@ -96,6 +96,7 @@
 packages/url_launcher/url_launcher_ios/**                @jmagman
 packages/video_player/video_player_avfoundation/**       @hellohuanlin
 packages/webview_flutter/webview_flutter_wkwebview/**    @hellohuanlin
+packages/pigeon/**/ios/**/*                              @hellohuanlin
 
 # - Linux
 packages/file_selector/file_selector_linux/**            @cbracken