superseeded by @pkgjs/support

[Eomm]

Opening this PR as follow up of this issue nodejs/package-maintenance#401

Notes:

these changes should be intended as major since the support format validated in this module is an old one and doesn't match the actual spec

For example, this was supported here but not by the @pkgjs/support

  "support": {
    "target": "NONE",
    "response": "BEST-EFFORT",
    "backing": "HOBBY"
  },

not sure if it has enough usage to warrant the extra effort here?)

The only option that is not supported by @pkgjs/support is the --file|-f <file path> arg, that could be replaced by the --base-path