Code split on route definition files

[zth]

Currently, each route renderer is code split, but the infra that loads each route is always emitted in one single file. This means that while we don't pay bundle costs for route renderers and how much code each route loads, we're still paying costs for every route we add, whether it's used or not.

I'd like to experiment with code splitting on route definition files. If this works out, it means we can replicate the "multiple entry points" pattern (like having a single app that has an admin section baked in for example) with very little bundle size cost. Which would be cool!

[Kingdutch]

Could we apply the same concept to a property in the routes definition (e.g. splitSubtree)? That way if it's more useful for my app I can still keep everything in a single routes file while benefitting from the app (but can also choose to split sub-apps in different files since we already have include).

[zth]

Yes, for sure! That's probably the better solution.

[zth]

I looked into this a bit, but it'll require quite a few changes. Postponing this because we have bigger fish to fry currently, and most of the pains this would solve was at least partially solved by #49