Minor dependency updates. Add "engines" for ESM-only. (#9)

- minor dependency updates
- saw a `node16 (from CJS) | ⚠️ ESM (dynamic import only)` warning at https://arethetypeswrong.github.io. The package.json looked good, so adding "engines" to make it explicit it's for Node 16+ which have better support for ESM to see if that fixes.

Author: briangershon