Feature request - support for plugins

[Rush]

In particular, this one would be useful.
https://github.com/metadevpro/ts-pegjs

[eploko]

Hey, @Rush, thanks for the head up. I didn't even know there were plugins for PEG.js :) Unfortunately, I'm not using the loader much myself these days and probably won't find enough courage to add the needed support for plugins myself. If someone provides a PR for this, I'll be more than happy to merge that in.

[Rush]

@eploko Thanks. I'll experiment with ts-pegjs and see if I can use your plugin as the base.