Mdatagen's usage output doesn't show a complete example

**Describe the bug**
Mdatagen's output doesn't show the the full example.

**Steps to reproduce**
`mdatagen -h`

**What did you expect to see?**
`Usage: ./mdatagen metadata.yaml`

**What did you see instead?**
`Usage of mdatagen:`

**What version did you use?**
Latest

**What config did you use?**
N/A

**Environment**
N/A

**Additional context**
N/A