Feature request: Don't assume everyone uses github

Many would prefer to use libre solutions for source control such as self hosted git or gitlab. Currently npm postclone requests a github username. It would probably be fine to just make the git username question optional.
As a workaround it's possible to just enter any name and change it in package.json later.

This name is used as plugin author in the package.json. Will fix the wording so it becomes clearer.