Update gemini.md

Author: hemang1729

docs/gateway/llm-provider-integrations/gemini.md

@@ -10,7 +10,7 @@ Visit the [Explorer Documentation](https://explorer.invariantlabs.ai/docs/explor
 ## Setup Gemini API Key
 
 ```bash
-export GEMINI_API_KEY={your-anthropic-api-key}
+export GEMINI_API_KEY={your-gemini-api-key}
 ```
 
 ## Code
@@ -62,4 +62,4 @@ This would push your trace to the [Invariant Explorer](https://explorer.invarian
     <span class='tile-description'>Enhance and debug your OpenAI Swarm agents effortlessly using the Gateway.</span>
 </a>
 
-</div>
+</div>