docs(stream.md): add streaming token usage info to docs

Closes https://github.com/BerriAI/litellm/issues/4904

docs/my-website/src/pages/stream.md

@@ -30,4 +30,48 @@ async def test_get_response():
 response = asyncio.run(test_get_response())
 print(response)
 
+```
+
+## Streaming Token Usage 
+
+Supported across all providers. Works the same as openai. 
+
+`stream_options={"include_usage": True}`
+
+If set, an additional chunk will be streamed before the data: [DONE] message. The usage field on this chunk shows the token usage statistics for the entire request, and the choices field will always be an empty array. All other chunks will also include a usage field, but with a null value.
+
+### SDK 
+```python 
+from litellm import completion 
+import os
+
+os.environ["OPENAI_API_KEY"] = "" 
+
+response = completion(model="gpt-3.5-turbo", messages=messages, stream=True, stream_options={"include_usage": True})
+for chunk in response:
+    print(chunk['choices'][0]['delta'])
+```
+
+### PROXY
+
+```bash 
+curl https://0.0.0.0:4000/v1/chat/completions \
+  -H "Content-Type: application/json" \
+  -H "Authorization: Bearer $OPENAI_API_KEY" \
+  -d '{
+    "model": "gpt-4o",
+    "messages": [
+      {
+        "role": "system",
+        "content": "You are a helpful assistant."
+      },
+      {
+        "role": "user",
+        "content": "Hello!"
+      }
+    ],
+    "stream": true,
+    "stream_options": {"include_usage": true}
+  }'
+
 ```