Add individual examples

Having one example per file will make for a integration and there
live demo links with CadHub.
Resolves #29.

examples/extrudeWithRadius.scad

@@ -0,0 +1,13 @@
+// extrudeWithRadius example
+
+include <Round-Anything-1.0.4/polyround.scad>
+
+radiiPoints=[
+    [-4,  0,  1   ],
+    [5,   3,  1.5 ],
+    [0,   7,  0.1 ],
+    [8,   7,  10  ],
+    [20,  20, 0.8 ],
+    [10,  0,  10  ]
+];
+extrudeWithRadius(3,0.5,0.5,5)polygon(polyRound(radiiPoints,30));