Adding OpenWrt support for Xiaomi AX3600 (Part 1)

Thank you @dimfish !

I had tried the instruction already - but without success.

It says "hold down the Reset button and power on the router then release it after 8 sec and wait for the router to flash the firmware."

Are the 8 seconds correct, or do I have to wait until the system LED starts flashing quickly?

On my router the system LED flashes quickly only for a couple of seconds and then turns to steady orange again.