Rename Pymem class constructor values to be more clear

[ughstudios]

def __init__(self, process_name=None):

Can we rename process_name to "process"? And then add type hints like so:

    def __init__(self, process: str | int):

[StarrFox]

this is definitely something that would be nice to change; however I feel it would require a major version release since the argument isn't positional only i.e. some people may be doing Pymem(process_name="abc.def")

can see this original discussion in #94