fix: make Accelerator alias of builtin string type (#179)

Co-authored-by: Samuel Attard <[email protected]>

Author: rhysd

base/base_inner.ts

@@ -1,10 +1,9 @@
   const NodeEventEmitter: typeof import('events').EventEmitter;
 
+  type Accelerator = string;
   type EmptyParams = {};
   type Event<Params extends object, Sender extends NodeJS.EventEmitter> = {
     preventDefault: () => void;
     readonly defaultPrevented: boolean;
     sender: Sender;
   } & Params;
-
-  class Accelerator extends String {}