chore(package): set engines to accurately represent node support

[Matthew-Mallimo]

Our engines field doesn't accurately represent the Node versions we support.
This fixes that by making it obvious that we only support 16 -> 18

[github-actions]

	Warnings
⚠️	Changes were made to package.json, but not to package-lock.json - Perhaps you need to run npm install?

Generated by 🚫 dangerJS against 44c1338

[github-actions]

Size Change: 0 B

Total Size: 712 kB

ℹ️ View Unchanged

Filename	Size
./build/app/app.js	164 kB
./build/app/app~vendors.js	411 kB
./build/app/runtime.js	7.07 kB
./build/app/service-worker-client.js	7.25 kB
./build/app/vendors.js	123 kB

_{compressed-size-action}