docs: add how-to for streaming tokens w/o langchain chat models (#972)

docs/mkdocs.yml

@@ -148,6 +148,7 @@ nav:
           - Stream full state: how-tos/stream-values.ipynb
           - Stream state updates: how-tos/stream-updates.ipynb
           - Stream LLM tokens: how-tos/streaming-tokens.ipynb
+          - Stream LLM tokens without LangChain models: how-tos/streaming-tokens-without-langchain.ipynb
           - Stream arbitrarily nested content: how-tos/streaming-content.ipynb
           - Configure multiple streaming modes: how-tos/stream-multiple.ipynb
           - Stream events from within tools: how-tos/streaming-events-from-within-tools.ipynb