Explain render modes better.

Author: photonstorm

src/const.js

@@ -27,7 +27,8 @@ var CONST = {
     ScaleModes: require('./renderer/ScaleModes'),
 
     /**
-     * AUTO Detect Renderer.
+     * This setting will auto-detect if the browser is capable of suppporting WebGL.
+     * If it is, it will use the WebGL Renderer. If not, it will fall back to the Canvas Renderer.
      *
      * @name Phaser.AUTO
      * @const
@@ -37,7 +38,8 @@ var CONST = {
     AUTO: 0,
 
     /**
-     * Canvas Renderer.
+     * Forces Phaser to only use the Canvas Renderer, regardless if the browser supports
+     * WebGL or not.
      *
      * @name Phaser.CANVAS
      * @const
@@ -47,7 +49,9 @@ var CONST = {
     CANVAS: 1,
 
     /**
-     * WebGL Renderer.
+     * Forces Phaser to use the WebGL Renderer. If the browser does not support it, there is
+     * no fallback to Canvas with this setting, so you should trap it and display a suitable
+     * message to the user.
      *
      * @name Phaser.WEBGL
      * @const
@@ -57,7 +61,9 @@ var CONST = {
     WEBGL: 2,
 
     /**
-     * Headless Renderer.
+     * A Headless Renderer doesn't create either a Canvas or WebGL Renderer. However, it still
+     * absolutely relies on the DOM being present and available. This mode is meant for unit testing,
+     * not for running Phaser on the server, which is something you really shouldn't do.
      *
      * @name Phaser.HEADLESS
      * @const