feat(dependencies): minimal default tag install (#3362)

src/lerobot/data_processing/__init__.py

@@ -11,3 +11,13 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
+"""
+Data processing utilities (annotation tools, dataset transformations).
+
+Available sub-modules (import directly)::
+
+    from lerobot.data_processing.sarm_annotations import ...
+"""
+
+__all__: list[str] = []