Allow option to specify changelog filename

[crookedneighbor]

Would be great to allow a command line argument to specify the filename. IE, something like:

$ changes --file-name "CHANGELOG.md"

[mantoni]

Makes sense. I'm busy now and away next week. If you have time to make a PR, that'd be great! Otherwise I'll look into this once I'm back. For this module, I'd prefer to use a minimal option parser, e.g. minimist.

[crookedneighbor]

👍 was going to suggest something similar.