Merge pull request #331 from Portkey-AI/fix/librechat-docs

librechat update

Author: narengogi

integrations/libraries/librechat.mdx

@@ -108,7 +108,7 @@ Edit your existing `.env` file at the project root (if the file does not exist,
 
 ```env .env
 PORTKEY_API_KEY=YOUR_PORTKEY_API_KEY
-PORTKEY_BASE_URL=https://api.portkey.ai/v1
+PORTKEY_GATEWAY_URL=https://api.portkey.ai/v1
 ```
 
 **Edit the `librechat.yaml` file**