docs: [torrust#49] add backup section

Author: josecelano

README.md

@@ -13,3 +13,4 @@ It's also used to track issues in production.
 - [Firewall](docs/firewall.md)
 - [Sample Commands](docs/sample_commands.md)
 - [Rollbacks](docs/rollbacks.md)
+- [Backups](docs/backups.md)

docs/backups.md

@@ -0,0 +1,33 @@
+# Backups
+
+## Backup Index Database
+
+```bash
+cd /home/torrust/github/torrust/torrust-demo/
+./share/bin/index-db-backup.sh 
+```
+
+## Check Backups Crontab Configuration
+
+```bash
+sudo crontab -e
+```
+
+You should see the [crontab.conf](../share/container/default/config/crontab.conf) configuration file.
+
+## Check Backups
+
+```bash
+ls -alt /home/torrust/backups
+total 26618268
+-rwxr-x--- 1 root    root        2342912 May 12 07:00 backup_2025-05-12_07-00-01.db
+-rwxr-x--- 1 root    root        2342912 May 12 06:00 backup_2025-05-12_06-00-02.db
+-rwxr-x--- 1 root    root        2342912 May 12 05:00 backup_2025-05-12_05-00-01.db
+-rwxr-x--- 1 root    root        2342912 May 12 04:00 backup_2025-05-12_04-00-01.db
+```
+
+YOu can also check the script output with:
+
+```bash
+tail /var/log/cron.log
+```