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/commander/index.js

@@ -0,0 +1,26 @@
+const { Argument } = require('./lib/argument.js');
+const { Command } = require('./lib/command.js');
+const { CommanderError, InvalidArgumentError } = require('./lib/error.js');
+const { Help } = require('./lib/help.js');
+const { Option } = require('./lib/option.js');
+
+/**
+ * Expose the root command.
+ */
+
+exports = module.exports = new Command();
+exports.program = exports; // More explicit access to global command.
+// createArgument, createCommand, and createOption are implicitly available as they are methods on program.
+
+/**
+ * Expose classes
+ */
+
+exports.Command = Command;
+exports.Option = Option;
+exports.Argument = Argument;
+exports.Help = Help;
+
+exports.CommanderError = CommanderError;
+exports.InvalidArgumentError = InvalidArgumentError;
+exports.InvalidOptionArgumentError = InvalidArgumentError; // Deprecated