chore(docs): update maintenance guide (#4093)

* Update maintenance guide

* Fix capitalisation

Author: jloh02

MAINTENANCE.md

@@ -4,15 +4,26 @@ Create a new issue on GitHub with this checklist after the finals every semester
 
 ## Every Year
 
-- [ ] Update academic year and semester in `website/src/config/app-config.json`, and add current academic year to archive years
-- [ ] In `app-config.json`, update `examAvailability` to include only the semesters where exam information is available
-- [ ] Update with next year's holiday data from academic calendar to `website/src/data/holidays.json`
-  - [ ] Singapore & NUS Holidays (e.g. Well-Being day): <https://www.nus.edu.sg/registrar/calendar>
-- [ ] Update `website/src/data/academic-calendar.json` with data for the new academic year
-- [ ] Add announcement to website by updating `website/src/data/holidays.json`
-- [ ] Update academic year in `scrapers/nus-v2/src/config.ts`
+### 1 week before NUS IT Data Update
+
+- **Prepare "PR1"**
+  - [ ] Update with next year's holiday data from academic calendar to `website/src/data/holidays.json` - Singapore & NUS Holidays (e.g. Well-Being day): <https://www.nus.edu.sg/registrar/calendar>
+  - [ ] Update academic year in `scrapers/nus-v2/src/config.ts`
+- **Prepare "PR2"**
+  - [ ] In `app-config.json`, update `examAvailability` to include only the semesters where exam information is available
+  - [ ] Update `website/src/data/academic-calendar.json` with data for the new academic year
+  - [ ] Add announcement to website by updating `website/src/data/holidays.json`
+
+### 1-2 days before NUS IT Data Update
+
+- [ ] **Merge "PR1"**
+- [ ] Push PR1 to production
+
+### Day of NUS IT Data Update
+
 - [ ] Ensure that scraper is scraping next AY's data. You can do so by checking the locally published JSON files, or visiting `https://api.nusmods.com/v2/20XX-20XX/` (e.g. [https://api.nusmods.com/v2/2022-2023/](https://api.nusmods.com/v2/2022-2023/))
 - [ ] On Vercel or `.env`: Update academic year in export service's environment variables
+- [ ] **Merge "PR2"** to Master > Production
 - [ ] Deploy! :tada: :tada:
 - [ ] Monitor Sentry and Telegram for issues