feat: initial CLI structure

- init: create plugin boilerplate
- install: install from local path with deps
- list: show installed plugins
- validate: check manyplug.json syntax

node_modules/fs-extra/lib/copy/index.js

@@ -0,0 +1,7 @@
+'use strict'
+
+const u = require('universalify').fromPromise
+module.exports = {
+  copy: u(require('./copy')),
+  copySync: require('./copy-sync')
+}