Add bindings to keyboard shortcuts

The default binding for keyboardOne is the default combination
for muting on Discord. This was explicitly chosen as a use case, and it
    might make people not have to tangle with creating custom
    keybindings in the .ini file.

src/overlaycontroller.h

@@ -135,6 +135,7 @@ private:
     void processMotionBindings();
     void processPushToTalkBindings();
     void processChaperoneBindings();
+    void processKeyboardBindings();
 
 public:
     OverlayController( bool desktopMode, bool noSound, QQmlEngine& qmlEngine );