move multiple audio device section around

diff --git a/_manual/07_working-with-sessions/06_the-new-session-dialog/01_audio-setup/01_using-more-than-one-audio-device.html b/_manual/03_setting-up-your-system/07_using_more_than_one_audio_device.html
similarity index 100%
rename from _manual/07_working-with-sessions/06_the-new-session-dialog/01_audio-setup/01_using-more-than-one-audio-device.html
rename to _manual/03_setting-up-your-system/07_using_more_than_one_audio_device.html