Update README.md

Author: AlexLynd

README.md

@@ -1,3 +1,3 @@
 # Nugget-Invader
 Welcome to the Nugget Invader repository! The Invader is a WiFi attack suite developed for the WiFi Nugget, an ESP8266 based platform designed to make it easy to learn wifi security and hardware development. 
-You can find code for a simple deauthentication proof of concept under the `Deauth-POC` folder.
+You can find code for a simple deauthentication proof of concept under the `Deauth-POC` folder, but you'll need to use an older version of the [ESP8266 SDK](https://github.com/espressif/ESP8266_NONOS_SDK/releases/tag/v2.0.0).