Update README.md

Mention Gowin

Author: sameer

README.md

@@ -28,6 +28,7 @@ Most free and open source HDMI source (computer/gaming console) implementations
 - [x] Altera (tested on [MKR Vidor 4000](https://store.arduino.cc/usa/mkr-vidor-4000))
 - [x] Xilinx (tested on [Spartan Edge Accelerator Board](https://www.seeedstudio.com/Spartan-Edge-Accelerator-Board-p-4261.html))
 - [ ] Lattice (unknown)
+- [ ] Gowin (WIP, active testing on Tang Nano 9K)
 
 ### To-do List (upon request)
 - [x] 24-bit color