docs(readme): add reference to RIOT OS LVGL Package
@@ -109,6 +109,7 @@ LVGL is available as:
- [NXP MCUXpresso component](https://www.nxp.com/design/software/embedded-software/lvgl-open-source-graphics-library:LITTLEVGL-OPEN-SOURCE-GRAPHICS-LIBRARY)
- [NuttX library](https://docs.lvgl.io/master/get-started/os/nuttx.html)
- [RT-Thread RTOS](https://docs.lvgl.io/master/get-started/os/rt-thread.html)
+- [RIOT OS package](https://doc.riot-os.org/group__pkg__lvgl.html#details)
- NXP MCUXpresso library
- CMSIS-Pack
