Add out of range exception handling

Added a new case in the switch statement to handle -3 return value. This will throw an "out of range" exception when the parameter is outside the acceptable limits.

index.js

@@ -177,6 +177,10 @@ const voicemeeter = {
                 // re-run this function to re-connect. will throw if not possible.
                 return voicemeeter.getRawParameterFloat(parameter);
             }
+            case -3: {
+                // out of range exception
+                throw "Parameter out of range";
+            }
 
             default: {
                 console.error("unknown return value", retval);