Wiki refresh (Hello Effects) (#161)

I am going through the beginner wiki pages and updating them so they are the same as the source code files in jme3test/helloworld.

In this one we just add some comments to mess around with water. 

jme3test/helloworld source code:
https://github.com/jMonkeyEngine/jmonkeyengine/blob/master/jme3-examples/src/main/java/jme3test/helloworld/HelloEffects.java

docs/modules/tutorials/pages/beginner/hello_effects.adoc

@@ -88,6 +88,28 @@ public class HelloEffects extends SimpleApplication {
     debris.getParticleInfluencer().setVelocityVariation(.60f);
     rootNode.attachChild(debris);
     debris.emitAllParticles();
+    
+//    ParticleEmitter water = 
+//            new ParticleEmitter("Emitter", ParticleMesh.Type.Triangle, 20);
+//    Material mat_blue = new Material(assetManager, 
+//            "Common/MatDefs/Misc/Particle.j3md");
+//    mat_blue.setTexture("Texture", assetManager.loadTexture(
+//            "Effects/Explosion/flame.png"));
+//    water.setMaterial(mat_blue);
+//    water.setImagesX(2); 
+//    water.setImagesY(2); // 2x2 texture animation
+//    water.setStartColor( ColorRGBA.Blue); 
+//    water.setEndColor( ColorRGBA.Cyan); 
+//    water.getParticleInfluencer().setInitialVelocity(new Vector3f(0, -4, 0));
+//    water.setStartSize(1f);
+//    water.setEndSize(1.5f);
+//    water.setGravity(0,1,0);
+//    water.setLowLife(1f);
+//    water.setHighLife(1f);
+//    water.getParticleInfluencer().setVelocityVariation(0.1f);
+//    water.setLocalTranslation(0, 6, 0);
+//    rootNode.attachChild(water);
+
   }
 }
 ----