Method initialize

packages/fairygui/src/render/RenderBridge.ts:75–77

* Initialize the bridge with a canvas * 使用画布初始化桥接

(canvas: HTMLCanvasElement)

     * 使用画布初始化桥接
     */
    public async initialize(canvas: HTMLCanvasElement): Promise<boolean> {
        return this._backend.initialize(canvas);
    }

    /**
     * Begin a new frame