Reworked the core examples to exclude contributed examples.

examples/Ex010_Defining_an_Edge_with_a_Spline.py

@@ -0,0 +1,27 @@
+import cadquery as cq
+
+# 1.  Establishes a workplane to create the spline on to extrude.
+# 1a. Uses the X and Y origins to define the workplane, meaning that the
+# positive Z direction is "up", and the negative Z direction is "down".
+s = cq.Workplane("XY")
+
+# The points that the spline will pass through
+sPnts = [
+    (2.75, 1.5),
+    (2.5, 1.75),
+    (2.0, 1.5),
+    (1.5, 1.0),
+    (1.0, 1.25),
+    (0.5, 1.0),
+    (0, 1.0)
+]
+
+# 2.  Generate our plate with the spline feature and make sure it is a
+#     closed entity
+r = s.lineTo(3.0, 0).lineTo(3.0, 1.0).spline(sPnts).close()
+
+# 3.  Extrude to turn the wire into a plate
+result = r.extrude(0.5)
+
+# Displays the result of this script
+show_object(result)