QoL proposal for Rumble: Heat cooldown indicator

A big part of the learning process for is keeping his heat in the 50-90% range until you want to hard all-in with his passive on-hit damage. Currently, there is nothing in-game that explains the rate or time before his heat starts to decay.

Now, if Rumble is at 60% or more heat this isn't much of an issue, since he can fire a harpoon once his heat ticks down, but it's still a piece of hidden information that has no reason to be hidden.

Even something as simple as a ticking indicator in Rumble's status bar would be sufficient for him to be able to maintain the sweetspot and make no difference for experienced players that would know that exact timing anyway. It would just lower his skill barrier at no cost for higher levels of play.