Your plugin is just a Node.js module. Every Node.js modules needs a
package.json file with some meta information about the module.
The plugin-template already included one, but you have to edit it so that it contains the information about your plugin like name, author, version, ...
You can read about it in the npm package.json documentation.
npm install something --save. With the
--saveoption npm will auto add the installed dependency in your