This allows require() and import to work for even better compatibility between CJS and ESM consumers.
I dislike that this kills our ability for top-level awaits in example.ts, but seeing as how my primary use case for this library is a commonjs module, I think this is a fair trade-off.
Also changed "messages" to not encapsulate its export under the name "messages" to remove some repetition in importing "messages" and still needing to do "messages." to get the methods out. Now it's simple to import each message by name or group them under something like "messages" as desired on a per-library-user basis.
Refs:
* https://www.kravchyk.com/typescript-npm-package-json-exports/
* https://arethetypeswrong.github.io/
* https://evertpot.com/universal-commonjs-esm-typescript-packages/
This gives better control over importing in non-module environments and removes the example code as the default import which was running when loading up the library.
