Demos: ensure all use fun main() = application {

- Adjust some demo window sizes.
- Replace Random.double by Double.uniform
- Tweak some demos so screenshots look more interesting

orx-shade-styles/src/jvmDemo/kotlin/DemoRadialGradient01.kt

@@ -3,17 +3,15 @@ import org.openrndr.color.ColorRGBa
 import org.openrndr.extra.shadestyles.radialGradient
 import kotlin.math.cos
 
-fun main() {
-    application {
-        program {
-            extend {
-                drawer.shadeStyle = radialGradient(
-                        ColorRGBa.PINK,
-                        ColorRGBa.PINK.toHSVa().shiftHue(180.0).shade(0.5).toRGBa(),
-                        exponent = cos(seconds)*0.5+0.5
-                )
-                drawer.rectangle(120.0, 40.0, 400.0, 400.0)
-            }
+fun main() = application {
+    program {
+        extend {
+            drawer.shadeStyle = radialGradient(
+                ColorRGBa.PINK,
+                ColorRGBa.PINK.toHSVa().shiftHue(180.0).shade(0.5).toRGBa(),
+                exponent = cos(seconds) * 0.5 + 0.5
+            )
+            drawer.rectangle(120.0, 40.0, 400.0, 400.0)
         }
     }
-}
+}