fix: runs again in commonJS and ESM

[mheob]

After the last fix, JavaScript files stopped working.
This is now fixed by splitting the source files into separate commonJS and ESM files.

Resolves #22
Resolves #23

Additional Notes

The following cases are working:

Test in Common JS: 'pnpm exec node foo.js':
{ name: 'pnpm', version: '8.4.0' }

Test in Common JS: 'pnpm exec node foo.cjs':
{ name: 'pnpm', version: '8.4.0' }

Test in ESM JS: 'pnpm exec node foo.mjs':
{ name: 'pnpm', version: '8.4.0' }

Test in TS: 'pnpm exec ts-node foo.ts':
{ name: 'pnpm', version: '8.4.0' }

Test in Common TS: 'pnpm exec ts-node foo.cts':
{ name: 'pnpm', version: '8.4.0' }

I am considering adding unit tests for this script (see #24).