Refactor Artplayer class to add keydown event listener

packages/artplayer/types/artplayer.d.ts

@@ -165,8 +165,8 @@ declare class Artplayer extends Player {
 
     readonly hotkey: {
         keys: Record<string, ((event: Event) => any)[]>;
-        add(key: number, callback: (this: Artplayer, event: Event) => any): Artplayer['hotkey'];
-        remove(key: number, callback: Function): Artplayer['hotkey'];
+        add(key: string, callback: (this: Artplayer, event: Event) => any): Artplayer['hotkey'];
+        remove(key: string, callback: Function): Artplayer['hotkey'];
     };
 
     readonly mask: Component;

packages/artplayer/types/events.d.ts

@@ -68,4 +68,5 @@ export type Events = {
     restart: [url: string];
     muted: [state: boolean];
     setBar: [type: Bar, percentage: number, event?: Event];
+    keydown: [event: KeyboardEvent];
 };