Update README

README.md

@@ -28,16 +28,16 @@ The easiest way to host the Cat Sitting Planner is via Docker.
 docker-compose up -d --build
 ```
 
-### 2. Persist Data
-The database is stored in `/app/data/dev.db` inside the container. To persist your plans and bookings, map a volume to `/app/data`:
+### 2. Persist & Backup Data (Important)
+All coordination data is stored in a single SQLite file at `/app/data/dev.db` inside the container. 
 
-**Example `docker-compose.yml` volume:**
-```yaml
-volumes:
-  - ./data:/app/data
-```
+To ensure your plans are safe:
+1. **Always map a volume** to `/app/data`.
+2. **Backups**: Simply copy the `dev.db` file from your host path (e.g., `/mnt/user/appdata/csp/dev.db`).
+3. **Upgrades**: As long as the volume mapping stays the same, your data will survive container updates.
+4. **Moving Systems**: If you move the app, copy your existing `dev.db` into the new host data folder **before** starting the container.
 
-If you are using Unraid or a custom path:
+**Example `docker-compose.yml` volumes:**
 ```yaml
 volumes:
   - /mnt/user/appdata/csp:/app/data