fix(package.json): Add 'types/*' to package exports

[jeffberry]

This fixes an issue that we are experiencing when setting moduleResolution in our tsconfig to NodeNext. When this is enabled, the module resolution will only allow importing from paths that are defined within the exports config. Because only types/index.d.ts is available for import, it is causing these kinds of embedded imports to fail:

import("@stitches/react/types/css-util").CSS

I think the alternative would be to ensure that all types are exported from the types/index.d.ts file.

[Achaak]

I confirm this need on my side to pass a lib in ESM and pass the moduleResolution in Node16

[yovanoc]

Please accept this PR

[smol-honk]

@peduarte who should we @ to get this looked at? Thank you again for your time! Love the library.

[jonathantneal]

This actually looks really good. If I can get some access, I could merge this and put it into a release.

[peduarte]

cc @hadihallak @StephenHaney

[fmal]

@hadihallak @StephenHaney could you please merge this in and put it into a canary release or give @jonathantneal access do do so? This doesn't seem like much effort and would unblock usage of stitches with TypeScript's moduleResolution other than node. I would really appreciate it ☮️