Sorting exports

[hugo-dlb]

Thanks for developing this sweet plugin!
Are there plans to sort exports as well? It is pretty common to wrap third-party libraries and re-export many components, this would be a possible use case.

[sbutterworth-beaches]

I'd love to have this as an optional feature as well. Maybe even a prettier-plugin-sort-exports since the rules for sorting exports would be somewhat different/trickier than imports (which can be natural sorted fairly easily).

[ekwoka]

I'd like this. Maybe I'll take a stab at it.

Would be nice for keeping barrel files clean and clear.