docs: add an example comparing LangGraph & LangGraph API (#764)

* docs: add an example comparing LangGraph & LangGraph API

* stash

* add cloud docs

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Co-authored-by: Harrison Chase <hw.chase.17@gmail.com>

docs/docs/cloud/concepts/index.md

@@ -37,11 +37,13 @@ The LangGraph Cloud API offers several features to support complex agent archite
 Streaming is critical for making LLM applications feel responsive to end users. When creating a streaming run, the streaming mode determines what data is streamed back to the API client. The LangGraph Cloud API supports five streaming modes. 
 
 - **values**: Stream the full state of the graph after each node is executed. See the [How-to Guide](../../how-tos/cloud_examples/stream_values/) for streaming values.
-- **messages**: Stream complete messages (at the end of node execution) as well as tokens for any messages generated inside a node. This mode is primarily meant for powering chat applications. See the [How-to Guide](../../how-tos/cloud_examples/stream_messages/) for streaming messages.
+- **messages**: Stream complete messages (at the end of node execution) as well as tokens for any messages generated inside a node. This mode is primarily meant for powering chat applications. This is only an option if your graph contains a `messages` key. See the [How-to Guide](../../how-tos/cloud_examples/stream_messages/) for streaming messages.
 - **updates**: Streams updates to the state of the graph after each node is executed. See the [How-to Guide](../../how-tos/cloud_examples/stream_updates/) for streaming updates.
-- **events**: Stream all events (including the state of the graph) after each node is executed. See the [How-to Guide](../../how-tos/cloud_examples/stream_events/) for streaming events.
+- **events**: Stream all events (including the state of the graph) after each node is executed. See the [How-to Guide](../../how-tos/cloud_examples/stream_events/) for streaming events. This can be used to do token-by-token streaming for LLMs.
 - **debug**: Stream debug events after each node is executed. See the [How-to Guide](../../how-tos/cloud_examples/stream_debug/) for streaming debug events.
 
+You can also specify multiple streaming modes at the same time.
+
 See the [API Reference](../reference/api_ref.md) for how to create streaming runs.
 
 ### Human-in-the-Loop

docs/mkdocs.yml

@@ -191,8 +191,9 @@ nav:
           - Run Multiple Agents in Thread: 'cloud/how-tos/cloud_examples/same-thread.ipynb'
           - Human in the loop: 'cloud/how-tos/cloud_examples/human-in-the-loop_cloud.ipynb'
           - Create Agents with Configuration: 'cloud/how-tos/cloud_examples/configuration_cloud.ipynb'
+          - Convert LangGraph calls to LangGraph Cloud calls: 'cloud/how-tos/cloud_examples/langgraph_to_langgraph_cloud.ipynb'
       - Conceptual Guides:
-          - API Concepts: 'cloud/concepts/api_concepts.md'
+          'cloud/concepts/index.md'
       - Reference:
           - API: 'cloud/reference/api_ref.md'
           - SDK: