feat(presidio_pii_masking.py): allow request level controls for turning on/off pii masking

https://github.com/BerriAI/litellm/issues/2003

litellm/proxy/proxy_server.py

@@ -3156,6 +3156,19 @@ async def generate_key_fn(
     - permissions: Optional[dict] - key-specific permissions. Currently just used for turning off pii masking (if connected). Example - {"pii": false}
     - model_max_budget: Optional[dict] - key-specific model budget in USD. Example - {"text-davinci-002": 0.5, "gpt-3.5-turbo": 0.5}. IF null or {} then no model specific budget.
 
+    Examples: 
+
+    1. Allow users to turn on/off pii masking
+
+    ```bash
+    curl --location 'http://0.0.0.0:8000/key/generate' \
+        --header 'Authorization: Bearer sk-1234' \
+        --header 'Content-Type: application/json' \
+        --data '{
+            "permissions": {"allow_pii_controls": true}
+    }'
+    ```
+
     Returns:
     - key: (str) The generated api key
     - expires: (datetime) Datetime object for when key expires.