Merge pull request #125 from Guozhanxin/master

更换 README.md 交流链接为 facebook

Author: Guozhanxin

README.md

@@ -86,7 +86,7 @@ sdk-bsp-stm32h750-realthread-artpi supports RT-Thread Studio and MDK development
 
 ART-Pi is an open source creative hardware platform. We look forward to having more friends who can discover more fun together. If you have any ideas and suggestions during use, we suggest you contact us through the following methods.
 
-RT-Thread [Community Forum](https://club.rt-thread.org/).
+RT-Thread [Facebook](https://www.facebook.com/RT-Thread-IoT-OS-110395723808463).
 
 ## Contributing code