[enh] Parse full URL in addition to "name/project"

[nyurik]

Please add a tiny improvement -- allow full URLs like https://github.com/ys/forked to be pasted, in addition to ys/forked. Ideally, in a very generic form:

Extract group 1 and 2 from ^https?:\/\/github\.com\/([^/]+)/([^/]+)(\/.*)?

This will allow event urls to sub-items, like https://github.com/ys/forked/issues to be used.

Thanks for an amazing project!!!