Typechecker

I was adding this to my builds: https://github.com/time4dev/vite-esbuild-typescript-checker

And I got this warning:

    sharp-collections doesn't appear to be written in CJS, but also doesn't appear to be a valid ES module (i.e. it doesn't have "type": "module" or an .mjs extension for the entry point). Please contact the package author to fix.

Is that a change you would consider?