adds Google Studio url to .env.local docs

Extends sample environment variable with Google Studio url

.env.example

@@ -28,7 +28,9 @@ OPEN_ROUTER_API_KEY=
 
 # Get your Google Generative AI API Key by following these instructions -
 # https://console.cloud.google.com/apis/credentials
-# You only need this environment variable set if you want to use Google Generative AI models
+# Get your Google Gemini API Key from the Google AI Studio dashboard -
+# https://aistudio.google.com/app/apikey
+# You only need this environment variable set if you want to use Google Generative AI models or Google Gemini models
 GOOGLE_GENERATIVE_AI_API_KEY=
 
 # You only need this environment variable set if you want to use oLLAMA models