GeezerVison

I'd like to propose some breaking changes:

1. Removed commitFilesFromBuffers and commitFilesFromDirectory. Through the recent refactors, you can see that they're a thin wrapper over the core commitFilesFromBase64.

   I don't think it's hard for users to use commitFilesFromBase64 directly, so I'd prefer if we consolidate to that.

2. Remove subpath exports, only use the main "." entrypoint.

   With exports conditions, it should be possible to split the API for browsers and node in the same subpath. Plus treeshaking works the same with this approach. You get the same small bundle size already if you only use one set of APIs.

Maybe I'd rename commitFilesFromBase64 to something more user-friendly I think, but I'd like to focus on the API trimming for now.