Over the past few days, I've whipped up a small, but useful dev environment for c3 addons.
It takes care of boilerplate addon dev setup. (Renaming IDs in files and more), setting up a cors enabled web server to host your files and automatically generates a .c3addon file when you're ready to export.
... with the following commands.
npm run create
npm run export
npm run dev-server
npm run test
There are more in "in depth" tutorials on Github.
I've only thoroughly tested the behavior and single global plugin creation and will continue to test and fix bugs for the next couple of days.
If you find anything that needs fixing, please let me know and create an issue on Github.
Or if you feel like contributing, please send over a pull request.
Have fun, Thanks!