Support dev flag in CLI

[Conduitry]

The new dev: true option in the compiler should be exposed in the CLI. I'm currently thinking a --dev/-d flag. I can work on a this if that sounds like how you want to handle this.

[Rich-Harris]

I was in this project updating the tests (expected output changed with recent versions) and this was a quick addition so I took care of it while I was here — released as 1.3.5