Add attribution for derived content from Upsy Desky documentation (#623)

docs/docs/getting-started.mdx

@@ -129,6 +129,10 @@ Congratulations 🎉 You have gone successfully through everything to get starte
 
 Affiliate links are used on this website to support the Home Assistant Glow 🌟 project. Some Ad-blockers might block these links, and thus they seem to appear broken. You will have to temporarily disable ad-blocker to open these links.
 
+:::note
+This page contains content derived from the [Upsy Desky documentation](https://upsy-desky.tjhorner.dev/) by [TJ Horner](https://github.com/tjhorner). The derived content is licensed under [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en).
+:::
+
 {/* Hardware */}
 [esp32-bg-shop]: https://www.banggood.com/bang/?tt=16956_12_417111_&r=https%3A%2F%2Fnl.banggood.com%2FGeekcreit-ESP32-WiFi%2Bbluetooth-Development-Board-Ultra-Low-Power-Consumption-Dual-Cores-Pins-Unsoldered-p-1214159.html
 [esp32-ali-shop]: https://tc.tradetracker.net/?c=15640&m=12&a=417111&r=&u=https%3A%2F%2Faliexpress.com%2Fitem%2F1005005970816555.html