style: ensure trailing newlines

src/jcloud_docsgen/exceptions.py

@@ -76,4 +76,4 @@ class PythonDefinitionError(ValueError):
         else:
             return f'{self.args[0]}{": " if self.definition and self.args[0] else ""}{self.definition if self.args[0] else ""}'
 
-class PythonArgumentStructureError(PythonDefinitionError): ...
+class PythonArgumentStructureError(PythonDefinitionError): ...