[V5] Validator Rule.url() for subdomains with _ character or wildcard

[HappyLDE]

Hi, amazing work so far on V5 it's great n' amazing.

Like title said, this subdomain: _.domain.tld should be valid.

Is there a rule to allow or disallow subdomains?
Also we need a rule to allow or disallow wildcard * subdomains

Let me know what you think!

PS: Used the last version of every package (did npm update).