Add note about "No audio device"

[ChucklesOnGitHub]

From Discord user ant_blot: On some (older) windows computer starting the gui crashes with "no audio device" message. It took us a while to realise that it was because of a Windows "feature". If there is no audio output (screen with DVI, no onboard speaker or headphone connected), windows disables completely the audio device (in the task bar the volume icon has a red cross like when it's on mute). The issue can be solved by connecting a jack cable in the headphone connector (no need to have speakers, just put something in the connector and let the cable hang loose and it works). It's not a gui issue per se but it might be good to add that in the documentation/troubleshooting somewhere