feat: refactor calendar

src/pages/background/lib/addCourse.ts

@@ -2,7 +2,11 @@ import { UserScheduleStore } from '@shared/storage/UserScheduleStore';
 import type { Course } from '@shared/types/Course';
 
 /**
- *
+ * Adds a course to a user's schedule.
+ * @param scheduleName - The name of the schedule to add the course to.
+ * @param course - The course to add.
+ * @returns A promise that resolves to void.
+ * @throws An error if the schedule is not found.
  */
 export default async function addCourse(scheduleName: string, course: Course): Promise<void> {
     const schedules = await UserScheduleStore.get('schedules');