npm script `start` has unreliable output

[lukemelia]

The start script in package.json concurrently runs start:types and start:js. The former clears the screen when done running, which means that it sometimes (race condition) will clear the output of the latter.

[lukemelia]

Seems like we need glint to have something like https://www.typescriptlang.org/tsconfig/#preserveWatchOutput

[NullVoxPopuli]

I opened an issuer here on glint, https://github.com/typed-ember/glint/issues/597

and @dfreeman mentioned the exact same thing! I personally haven't had the time to forward the flag, but a PR would be very welcome <3