updated text and describe

Author: aceslowman

src/data/examples/en/20_3D/12_simple_feedback.js

@@ -1,7 +1,10 @@
 /*
  * @name Simple Feedback
  * @arialabel An example of a simple feedback effect using two buffers.
- * @description A simple feedback effect can be achieved through WEBGL mode and two graphics buffers.
+ * @description A simple feedback effect that is achieved by using two WebGL graphics buffers.
+ *              This effect works by drawing the previous frame to a second
+ *              createGraphics() buffer, which can be blended with the current frame. This 
+ *              takes advantage of texture mapping in WebGL.
  */
 
 let pg, swap;
@@ -15,7 +18,7 @@ function setup() {
   swap = createGraphics(710, 400, WEBGL);
 
   describe(
-    'a WebGL example that achieves a simple feedback effect, displaying a slowly moving, radiating white sphere.'
+    'a slowly oscillating, radiating white sphere that fades into a dark gray background through a feedback visual effect'
   );
 }