Make `UnicodeRegex` or `CodeRegex` optionally disableable.

[rdbisme]

Is there an easy way to enable just one of the regexes? My use case is that I'd like to lint allowing only CodeRegex matching commits, and not Unicode.

[arvinxx]

I think yes.

[rdbisme]

I think yes.

Oh cool, how? :)

[arvinxx]

https://github.com/arvinxx/gitmoji-commit-workflow/blob/master/packages/commitlint-plugin/src/rule.ts

The validation of emoji code is separated. So what we need to do is add a config to just skip unicode check.