$ missing.md --report json
[exit 2]
--- stdout
{
  "version": "0.2",
  "files": [],
  "skipped": [],
  "errors": [
    {
      "file": "missing.md",
      "message": "no such file or directory"
    }
  ],
  "summary": {
    "files": 1,
    "analyzed": 0,
    "passed": 0,
    "failed": 0,
    "skipped": 0,
    "errors": 1,
    "max_grade": null
  }
}
--- stderr
papa: missing.md: no such file or directory
