Add descriptions to demos

orx-shapes/src/jvmDemo/kotlin/hobbycurve/DemoHobbyCurve05.kt

@@ -0,0 +1,38 @@
+package hobbycurve
+
+import org.openrndr.application
+import org.openrndr.color.ColorRGBa
+import org.openrndr.extra.color.presets.WHITE_SMOKE
+import org.openrndr.extra.noise.simplex
+import org.openrndr.extra.noise.uniform
+import org.openrndr.extra.shapes.hobbycurve.hobbyCurve
+import org.openrndr.extra.shapes.ordering.hilbertOrder
+import org.openrndr.math.Vector2
+
+/**
+ * Demonstrates the creation of a 40 hobby curves with 10 points each.
+ * The control points in all hobby curves are almost identical, varying only
+ * due to a slight increase in one of the arguments of a simplex noise call.
+ *
+ * The program shows that minor displacements in control points can have
+ * a large impact in the resulting curve.
+ */
+fun main() = application {
+    program {
+        val seed = 68040
+        val curves = List(40) { n ->
+            hobbyCurve(List(10) {
+                Vector2(
+                    simplex(seed, it * 13.3, n * 0.001) * 300.0 + 320.0,
+                    simplex(seed / 2, it * 77.4, n * 0.001) * 300.0 + 240.0
+                )
+            }.hilbertOrder(), true)
+        }
+        extend {
+            drawer.clear(ColorRGBa.WHITE_SMOKE)
+            drawer.fill = null
+            drawer.stroke = ColorRGBa.BLACK.opacify(0.3)
+            drawer.contours(curves)
+        }
+    }
+}