[orx-color] Fix misplaced demo comments

orx-color/src/jvmDemo/kotlin/histogram/DemoHistogram01.kt

@@ -1,9 +1,14 @@
-package histogram// Show color histogram of an image
+package histogram
 
 import org.openrndr.application
 import org.openrndr.draw.loadImage
 import org.openrndr.extra.color.statistics.calculateHistogramRGB
 
+/*
+ * Demonstrates how to generate a palette with the top 32 colors
+ * of a loaded image, sorted by luminosity. The colors are displayed
+ * as rectangles overlayed on top of the image.
+ */
 fun main() = application {
     configure {
         width = 720

orx-color/src/jvmDemo/kotlin/histogram/DemoHistogram02.kt

@@ -1,10 +1,14 @@
-package histogram// Show color histogram using non-uniform weighting
+package histogram
 
 import org.openrndr.application
 import org.openrndr.draw.loadImage
 import org.openrndr.extra.color.statistics.calculateHistogramRGB
 import kotlin.math.pow
 
+/*
+ * Show the color histogram of an image using non-uniform weighting,
+ * prioritizing bright colors.
+ */
 fun main() = application {
     configure {
         width = 720

orx-color/src/jvmDemo/kotlin/histogram/DemoHistogram03.kt

@@ -1,9 +1,16 @@
-package histogram// Create a simple rectangle composition based on colors sampled from image
+package histogram
 
 import org.openrndr.application
 import org.openrndr.draw.loadImage
 import org.openrndr.extra.color.statistics.calculateHistogramRGB
 
+/*
+ * Create a simple grid-like composition based on colors sampled from image.
+ * The cells are 32 by 32 pixels in size and are filled with a random sample
+ * taken from the color histogram of the image.
+ *
+ * Note: due to its random nature the resulting animation contains flickering colors.
+ */
 fun main() = application {
     configure {
         width = 720