Feat: lots of things, preparing for live gig

src/state/audio.rs

@@ -83,6 +83,7 @@ pub struct AudioConfig {
     pub refresh_rate: RefreshRate,
     pub show_scope: bool,
     pub show_spectrum: bool,
+    pub show_preview: bool,
     pub layout: MainLayout,
 }
 
@@ -101,6 +102,7 @@ impl Default for AudioConfig {
             refresh_rate: RefreshRate::default(),
             show_scope: true,
             show_spectrum: true,
+            show_preview: true,
             layout: MainLayout::default(),
         }
     }