Redis Suggestion for each publish and subscribe as ACL_CATEGORY

Hello, While operating redis instances, I've found some improvements.

We are now using acl user for write-user and readonly-user like below:

1) "user write-user on ########## ~* &* +@all"
2) "user readonly-user on ########## ~* &* -@all +@read +@connection +@pubsub +cluster"

The purpose is to split permissions-read,write-for higher security.

And I think that something is weird about "pubsub", because it is containing both of write and read-publish and subscribe. To be precise, the command "publish" will be thought to be "write". ASIS command_flags just configure about PUBSUB or not, so I would like to suggest about adding "ACL_CATEGORY_PUBLISH" and "ACL_CATEGORY_SUBSCRIBE" to ACLDefaultCommandCategories.

I can make own build for our services, but I would be glad if I could apply this options also in opensource redis. May I make branch for it? If this issue is duplicated or there are some reasons for not spliting this permissions, then please let me know about it.

Best regards,