Re-add docstring

Author: BenjaminCharmes

pydatalab/src/pydatalab/models/export_task.py

@@ -5,13 +5,17 @@
 
 
 class ExportStatus(str, Enum):
+    """Status of an export task."""
+
     PENDING = "pending"
     PROCESSING = "processing"
     READY = "ready"
     ERROR = "error"
 
 
 class ExportTask(BaseModel):
+    """Model for an export task."""
+
     task_id: str = Field(..., description="Unique identifier for the export task")
     collection_id: str | None = Field(None, description="ID of the collection being exported")
     item_id: str | None = Field(None, description="ID of the sample being exported")