Please add dojo-webpack-plugin to list of plugins #100

Proposed changes can be seen here: https://github.com/chuckdumont/docs/wiki/list-of-plugins#dojowebpackplugin-

Note that I'm requesting this change in the old document repo because the plugin currently only works with Webpack 1.x. I'm assuming that only plugins supporting Webpack 2.x go in the new documentation. Please correct me if I'm wrong about that.