[orx-noise] Tidy up demos

Produce 720px wide images.
Use main() = application { for reduced indentation

orx-noise/src/jvmDemo/kotlin/DemoGradientPerturb3D.kt

@@ -6,22 +6,25 @@ import org.openrndr.extra.noise.simplex
 import org.openrndr.math.Vector3
 import kotlin.math.absoluteValue
 
-fun main() {
-    application {
-        program {
-            val cb = colorBuffer(width, height)
-            val shad = cb.shadow
-            extend {
-                for (y in 0 until height) {
-                    for (x in 0 until width) {
-                        val p = gradientPerturbFractal(300, frequency = 0.8, position = Vector3(x/320.0,y/240.0, seconds))
-                        val d = simplex(300, p.x, p.y, p.z).absoluteValue
-                        shad[x, y] = ColorRGBa(d, d, d, 1.0)
-                    }
+fun main() = application {
+    configure {
+        width = 720
+        height = 360
+    }
+    program {
+        val cb = colorBuffer(width, height)
+        val shad = cb.shadow
+        extend {
+            for (y in 0 until height) {
+                for (x in 0 until width) {
+                    val p =
+                        gradientPerturbFractal(300, frequency = 0.8, position = Vector3(x / 320.0, y / 240.0, seconds))
+                    val d = simplex(300, p.x, p.y, p.z).absoluteValue
+                    shad[x, y] = ColorRGBa(d, d, d, 1.0)
                 }
-                shad.upload()
-                drawer.image(cb)
             }
+            shad.upload()
+            drawer.image(cb)
         }
     }
-}
+}