Better API for error messages with help

This feels unnecessarily long-winded. Couldn't I just do:
```suggestion
    help({
      error: `Expected a command, but the value was empty`, 
      description: false,
    });
```
?

_Originally posted by @SeparateRecords in https://github.com/SeparateRecords/run-fig/pull/12#discussion_r962134703_