Our structure has a dev and a prod folder.

Since recent changes (T118894), the only way to develop has been to build the production version.

This has 2 major issues:

• the production version only has minified assets, which makes development/troubleshooting harder.
• many tasks required to output the production version can be avoided when developing a feature.

This ticket is to bring back a development version (with non-minified assets), as well as a gulp task that watches for file changes and builds the development version.
This will make development a lot easier/better/faster.