Document api modules and require explicit imports of API submodules

src/ifcopenshell-python/ifcopenshell/api/document/__init__.py

@@ -16,6 +16,15 @@
 # You should have received a copy of the GNU Lesser General Public License
 # along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
 
+"""Reference external project documents and associate them to model elements
+
+Some project information (drawings, specifications, certificates, reports, etc)
+may be stored in external documents (locally or in a CDE). IFC lets you store a
+register of documents with metadata and associate them with elements (both
+physical and non-physical).
+"""
+
+from .. import wrap_usecases
 from .add_information import add_information
 from .add_reference import add_reference
 from .assign_document import assign_document
@@ -24,3 +33,5 @@ from .edit_reference import edit_reference
 from .remove_information import remove_information
 from .remove_reference import remove_reference
 from .unassign_document import unassign_document
+
+wrap_usecases(__path__, __name__)