Document api modules and require explicit imports of API submodules

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

@@ -16,6 +16,14 @@
 # You should have received a copy of the GNU Lesser General Public License
 # along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
 
+"""Manage visual styles of geometry (colours, transparency, rendering, etc)
+
+Geometry may have visual styles associated with it, including surface styles,
+2D curve styles, text styles, and more. Surface styles are most commonly used
+for simple colouring.
+"""
+
+from .. import wrap_usecases
 from .add_style import add_style
 from .add_surface_style import add_surface_style
 from .add_surface_textures import add_surface_textures
@@ -28,3 +36,5 @@ from .remove_styled_representation import remove_styled_representation
 from .remove_surface_style import remove_surface_style
 from .unassign_material_style import unassign_material_style
 from .unassign_representation_styles import unassign_representation_styles
+
+wrap_usecases(__path__, __name__)