Update API doc page

Onur Rauf Bingol · Onur Rauf Bingol · commit 1427ab2e6f34 · 2019-05-20T12:10:56.000-05:00
diff --git a/docs/api.rst b/docs/api.rst
@@ -4,6 +4,9 @@ API Documentation
 Class Reference
 ===============
 
+Analytic Geometry
+-----------------
+
 .. automodule:: geomdl.shapes.analytic
     :members:
     :inherited-members:
@@ -12,16 +15,25 @@ Class Reference
 Function Reference
 ==================
 
+Curves
+------
+
 .. automodule:: geomdl.shapes.curve2d
     :members:
     :inherited-members:
     :show-inheritance:
 
+Surfaces
+--------
+
 .. automodule:: geomdl.shapes.surface
     :members:
     :inherited-members:
     :show-inheritance:
 
+Volumes
+-------
+
 .. automodule:: geomdl.shapes.volume
     :members:
     :inherited-members:
