I understand this is probably because most people use bundle.js for packaging... but oh god this took me 20 minutes of time wasting to figure out what was going wrong with my editor.

Do we need to special case this?
Doesn't everyone separate their source folders from distribution anyway?
In which case, if this is an issue, they can just do standard src/.

All the other defaults:

node_modules/*, .min.js, bundle.js, coverage/

I don't think would ever get in the way.