Documentation error: flip params are wrong

# Expected Behavior

documentation should be correct

# Current Behavior

Correct:
image.flip({horizontal: true, vertical: false});

# Failure Information (for bugs)

documentation states:

cloned.flip(true, false);

which throws

## Steps to Reproduce

try as suggested in docs:

cloned.flip(true, false);

=> throw

cloned.flip({horizontal: true, vertical: false}); // works

- Jimp Version: 1.6
- Node version: 20