docs(call_hooks.md): show admin how to enforce user param

docs/my-website/docs/proxy/call_hooks.md

@@ -2,6 +2,7 @@
 
 - Modify data before making llm api calls on proxy
 - Reject data before making llm api calls / before returning the response 
+- Enforce 'user' param for all openai endpoint calls
 
 See a complete example with our [parallel request rate limiter](https://github.com/BerriAI/litellm/blob/main/litellm/proxy/hooks/parallel_request_limiter.py)
 
@@ -172,4 +173,15 @@ curl --location 'http://0.0.0.0:4000/chat/completions' \
         }
     ],
     }'
+```
+
+## Advanced - Enforce 'user' param 
+
+Set `enforce_user_param` to true, to require all calls to the openai endpoints to have the 'user' param. 
+
+[**See Code**](https://github.com/BerriAI/litellm/blob/4777921a31c4c70e4d87b927cb233b6a09cd8b51/litellm/proxy/auth/auth_checks.py#L72)
+
+```yaml
+general_settings:
+  enforce_user_param: True
 ```

docs/my-website/docs/proxy/configs.md

@@ -602,6 +602,7 @@ general_settings:
     "disable_spend_logs": "boolean", # turn off writing each transaction to the db
     "disable_reset_budget": "boolean", # turn off reset budget scheduled task
     "enable_jwt_auth": "boolean", # allow proxy admin to auth in via jwt tokens with 'litellm_proxy_admin' in claims
+    "enforce_user_param": "boolean", # requires all openai endpoint requests to have a 'user' param
     "allowed_routes": "list", # list of allowed proxy API routes - a user can access. (currently JWT-Auth only)
     "key_management_system": "google_kms", # either google_kms or azure_kms
     "master_key": "string",