make explosion rumble distance change mid-way through

src/main/java/dev/isxander/controlify/rumble/RumbleState.java

@@ -1,4 +1,7 @@
 package dev.isxander.controlify.rumble;
 
 public record RumbleState(float strong, float weak) {
+    public RumbleState mul(float multiplier) {
+        return new RumbleState(strong * multiplier, weak * multiplier);
+    }
 }