finish the DRIdoc

Writing-DRI-Engine-Driver-for-Your-GPU.md

@@ -8,6 +8,7 @@ Table of Contents
   * [Implement DRI driver](#implement-dri-driver)
   * [Restrictions](#restrictions)
 - [Example](#example)
+- [Future Feature](#future-feature)
 
 ## Overview
 
@@ -259,14 +260,13 @@ Note that MiniGUI does not defined the detailed structure of
 
 For other operators, please see the comments above.
 
-
 ### Restrictions
 
 In version 4.0.0, the `dri` NEWGAL engine does not provide support for
 MiniGUI-Processes run-time mode. We will enhance this in the subsequent
 version of MiniGUI.
 
-Also note that when you use the hardware accelerated sub driver, MiniGUI app
+Also note that when you use the hardware accelerated driver, MiniGUI app
 may need the root privilege to call `drmSetMaster` to set the video mode.
 However, under MiniGUI-Processes run-time mode, only the server (`mginit`) will
 need this privilege when you use the future `dri` engine.
@@ -283,9 +283,9 @@ https://github.com/VincentWei/mg-tests/tree/master/dri-engine
 In the near future, the MiniGUI team will:
 
 * Enhance `dri` engine to support MiniGUI-Processes run-time mode.
-* Implement the MiniGUI back-end of `cairo` and MiniGUI EGL for OpenGL,
+* Implement the MiniGUI back-end of `cairo` and `EGL` for OpenGL,
   OpenGL ES, and OpenVG, in order to fully exploit the GPU's 2D/3D
   accelerated rendering capabilities.
-
-We will provide some samples in `mg-tests` or `mg-samples` for this purpose.
+* Provide some samples in `mg-tests` or `mg-samples` to integrate
+  MiniGUI with `cairo` and OpenGL/OpenGL ES/OpenVG.