Document possible Babel customizations

[leodr]

I'm building a package with @emotion/react and need to include their babel-plugin.

I've read on some issues here that Babel customization is possible with a .babelrc file, but it is not documented anywhere. And is the Babel configuration getting merged in or replaces the default one?

I'd also write the docs for that if someone can point me in the right direction :)

[ymeskini]

So I had the same issue on that part for example to enable automatic jsx runtime, microbundle is building the babel configuration based on what arguments you passed (cf. https://github.com/developit/microbundle#all-cli-options-) I had to pass --jsxImportSource to enable it