add REXPaint (#173)

README.md

@@ -148,6 +148,7 @@ Graphics
 * :free: [project one](http://p1.untergrund.net) - A picture converter and editor for the Commodore 64 covering different graphics mode of this computer. Windows only
 * :moneybag: [PXL8](http://www.pxl8.it) - A cross platform (Windows, Mac, Linux) pixel art editor in development which aims to be distraction free
 * :moneybag: [PyxelEdit](http://pyxeledit.com/) - Pixel art editor designed to make it fun and easy to make tilesets, levels and animations.
+* :free: [REXPaint](https://www.gridsagegames.com/rexpaint/) - a powerful and user-friendly ASCII art editor.
 * :free: [Timanthes](http://csdb.dk/release/?id=75871) - A pixel art editor for the Commodore 64 computer running on Windows
 * [Charas](http://charas-project.net/index.php) - Charas is a charset generator for RPG Maker.
 * [Loose Leaf](http://www.geocities.jp/kurororo4/looseleaf/) - Sprite character generator

README_ch.md

@@ -156,6 +156,7 @@
 * [project one](http://p1.untergrund.net) - 一款面向 Commodore 64 平台的图像格式转换工具，覆盖该平台上各种不同的图形格式。该软件只能在 Windows 上运行。
 * [PXL8](http://www.pxl8.it) - 一款跨平台(Windows, Mac, Linux)像素绘画编辑器，面向免费分发。 ![commercial](/img/commercial.png)
 * [PyxelEdit](http://pyxeledit.com/) - 像素绘制编辑器，能够有趣并简便地制作瓷片地图集、关卡和动画。 ![commercial](/img/commercial.png)
+* [REXPaint](https://www.gridsagegames.com/rexpaint/) - 一款强大的 ASCII 绘图工具。
 * [Timanthes](http://csdb.dk/release/?id=75871) - 一款运行在 Windows 平台上的面向 Commodore 64 平台的像素绘制编辑器。
 
 #### 建模