Clarify what off('*') does

Fixes #150

Author: developit

src/index.ts

@@ -70,7 +70,7 @@ export default function mitt<Events extends Record<EventType, unknown>>(
 		/**
 		 * Remove an event handler for the given type.
 		 * If `handler` is omitted, all handlers of the given type are removed.
-		 * @param {string|symbol} type Type of event to unregister `handler` from, or `'*'`
+		 * @param {string|symbol} type Type of event to unregister `handler` from (`'*'` to remove a wildcard handler)
 		 * @param {Function} [handler] Handler function to remove
 		 * @memberOf mitt
 		 */