Add license file to default project and to bower.json

[paf31]

Some young PureScript projects lack a license file, and I think this would help. It could default to All Rights Reserved (and perhaps note that on the console too?), but I think having it there would encourage users to think about licensing.

[hdgarrood]

I don't think it's a problem that some projects lack a license file; if I remember correctly this was a conscious decision we made to allow projects to not have a license file if they have a recognisable SPDX expression in the license field of bower.json, during purs publish.

I think we probably do enough to encourage users to think about licensing already, in that purs publish (and consequently also pulp version and pulp publish, which use purs publish --dry-run and purs publish respectively) fail if you don't have an acceptable SPDX expression in bower.json, although I suppose it wouldn't hurt to log something like this after a successful pulp init:

consider adding a license in bower.json; for example: "license": "MIT"