rfc/methods.md: Review contribution

For abstract methods, specify that they don't take a signature in the defining sentence.
add "same" to clarify which namespace private methods are defined in.
s/subclass/parent class/ (you inherit from parent classes!)
"Roles cannot require private methods" is valid beyond the MVP: Since roles can't call private methods of consuming classes, they can't make use of them, so there's no justification to require them.
In the code example, "does ROLE" has been changed to ":does(ROLE)
I've deleted the Moose example for "private methods". It is not needed but has some issues: 1) Less::Boilerplate is unspecified 2) excluding a private method is a code smell (consider renaming the private method in the consuming class instead) 3) Role authors should safeguard their "private methods" by writing them as lexical subs and calling them as subs, not as methods. There should be no inheritance for private methods, so no method resolution is needed and nothing is lost.

Perl-Apollo / Corinna