typings don't allow signals without parameters

[jmlee2k]

example:

import { MiniSignal } from "mini-signals";

const noParamSignal = new MiniSignal<never>();
noParamSignal.add(()=>console.log(`recieved`));

//Argument of type '[]' is not assignable to parameter of type 'never'.ts(2345)
noParamSignal.dispatch();

I believe the general solution may be to switch the T generic from:

T extends any[] = any[]

to

T extends any[] | void = void

but this is complicated by the fact that the dispatch method expects an array (due to it's use of the spread syntax)