Zipping sources for firefox in turborepo monorepo

[stevezhu]

The default source zipping behavior in wxt doesn't consider locally imported packages in a turbo monorepo, so I wrote some hooks to handle generating sources for submission to firefox addons in case anyone else is also running into this. Feel free to package this into a wxt module.

Edit: turned into a package https://www.npmjs.com/package/wxt-turbo