docs update
If you are reloading a Phaser Game on a page that never properly refreshes (such as in an AngularJS project) then you will quickly run out of AudioContext nodes. If this is the case create a global var called `PhaserGlobal` on the window object before creating the game. The active AudioContext will then be saved to `window.PhaserGlobal.audioContext` when the Phaser game is destroyed, and re-used when it starts again (#1233)