I would like to adjust the likelihood of mommy's moods

The docs explain that I can adjust mommy's moods with `CARGO_MOMMYS_MOODS="chill/ominous"` (which randomly selects one of these moods for each invocation.)

I would like to have mommy be chill most of the time but occasionally be ominous.

I _think_ I can accomplish this with an env variable like `CARGO_MOMMYS_MOODS="chill/chill/chill/ominous"`, but it would be nice to be certain.

