added some screenshots for the linux-audio workshop

...ktop_Slideshow/linux-audio/audio-alsa_basic_structure.jpg

...enation/Desktop_Slideshow/linux-audio/audio-alsamixer.png

...Desktop_Slideshow/linux-audio/audio-ardour2-workbench.png

...ideshow/linux-audio/audio-audacity-record-edit-stereo.png

...ktop_Slideshow/linux-audio/audio-hydrogen-drummachine.png

...nation/Desktop_Slideshow/linux-audio/audio-linux-mess.png

Praesenation/Desktop_Slideshow/linux-audio/audio-paprefs.png

...sktop_Slideshow/linux-audio/audio-patchage-less-messy.png

...ideshow/linux-audio/audio-simplejack-default-settings.png

...ion/Desktop_Slideshow/linux-audio/audio-vulkan-layers.png