Add name and scope to init config

[wraithgar]

When running npm init it's not currently possible to set the package name via config. An --init-name flag seems like it should exist.

Additionally, having a scope configured for init to use when it auto defines the name based on the directory seems like a good idea.

$ mkdir foo
$ cd foo
$ npm init --init-scope=@gar -y

... should make a package name @gar/foo