Add note about deleting old certbot domains

README.md

@@ -51,3 +51,9 @@ If you need to update the web server with changes from the repository:
 cd /var/www/2025.fossy.us
 sudo -u www-data git pull
 ```
+
+Don't forget to **remove** the old LetsEncrypt certificate config if the archive will live on another server.
+
+```
+sudo certbot delete
+```