feat: show merging user instead of OP

src/services/webhook.service.ts

@@ -26,6 +26,7 @@ type BaseEvent = {
   user: User;
   html_url: string;
   body: string | null;
+  merged_by?: User | null;
 };
 
 @Injectable()
@@ -201,12 +202,13 @@ export class WebhookService {
   }
 
   private getEmbed(action: string, repositoryName: string, title: string, event: BaseEvent) {
+    const user = event.merged_by ? event.merged_by : event.user;
     return new EmbedBuilder({
       title: `[${repositoryName}] ${title} ${action}: #${event.number} ${event.title}`,
       author: {
-        name: event.user.login,
-        url: event.user.html_url,
-        iconURL: event.user.avatar_url,
+        name: user.login,
+        url: user.html_url,
+        iconURL: user.avatar_url,
       },
       url: event.html_url,
       description: