Added support for configuring the exclude rule of the webpack config

[KarlGe]

I've been struggling for days to get Next JS to play nice with untranspiled Linaria files in a component library that we're building, until I finally came across this discussion in the Linaria repo https://github.com/callstack/linaria/issues/178#issuecomment-761773489

The last missing piece here, then, is being able to configure the exclude of the linaria webpack rule. Since Linaria has it's own array of rules, I thought this approach could be useful for allowing to override both in one go.

I've tested it with https://github.com/martpie/next-transpile-modules, which works just fine!

Let me know what you think!