Convert README to markdown
This will look nicer on https://gitlab.freedesktop.org/xorg/driver/xf86-video-amdgpu/tree/master .
Due to an influx of spam, we have had to impose restrictions on new accounts. Please see this wiki page for instructions on how to get full permissions. Sorry for the inconvenience.
This will look nicer on https://gitlab.freedesktop.org/xorg/driver/xf86-video-amdgpu/tree/master .