Add individual examples

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

examples/polyRoundExtrude.scad

@@ -0,0 +1,13 @@
+// polyRoundExtrude example
+
+include <Round-Anything-1.0.4/polyround.scad>
+
+radiiPoints=[
+    [10, 0,  10 ],
+    [20, 20, 1.1],
+    [8,  7,  10 ],
+    [0,  7,  0.3],
+    [5,  3,  0.1],
+    [-4, 0,  1  ]
+];
+polyRoundExtrude(radiiPoints,2,0.5,-0.8,fn=20);