Merge pull request #2709 from langchain-ai/eugene/update_index_page

langgraph: update index page

docs/docs/how-tos/human_in_the_loop/time-travel.ipynb

@@ -10,7 +10,8 @@
     "!!! tip \"Prerequisites\"\n",
     "\n",
     "    This guide assumes familiarity with the following concepts:\n",
-    "    \n",
+    "\n",
+    "    * [Time Travel](../../../concepts/time-travel)\n",
     "    * [Breakpoints](../../../concepts/breakpoints)\n",
     "    * [LangGraph Glossary](../../../concepts/low_level)\n",
     "\n",

docs/docs/how-tos/index.md

@@ -48,13 +48,25 @@ LangGraph makes it easy to manage conversation [memory](../concepts/memory.md) i
 [Human-in-the-loop](../concepts/human_in_the_loop.md) functionality allows
 you to involve humans in the decision-making process of your graph. These how-to guides show how to implement human-in-the-loop workflows in your graph.
 
-- [How to edit graph state](human_in_the_loop/edit-graph-state.ipynb)
-- [How to wait for user input using `interrupt`](human_in_the_loop/wait-user-input.ipynb)
-- [How to view and update past graph state](human_in_the_loop/time-travel.ipynb)
-- [How to review tool calls](human_in_the_loop/review-tool-calls.ipynb)
+
+Key workflows:
+
+- [How to wait for user input](human_in_the_loop/wait-user-input.ipynb): A basic example that shows how to implement a human-in-the-loop workflow in your graph using the `interrupt` function.
+- [How to review tool calls](human_in_the_loop/review-tool-calls.ipynb): Incorporate human-in-the-loop for reviewing/editing/accepting tool call requests before they executed using the `interrupt` function.
+
+
+Other methods:
+
 - [How to add static breakpoints](human_in_the_loop/breakpoints.ipynb): Use for debugging purposes. For [**human-in-the-loop**](../concepts/human_in_the_loop.md) workflows, we recommend the [`interrupt()`](../../../reference/types/#langgraph.types.interrupt) function instead.
+- [How to edit graph state](human_in_the_loop/edit-graph-state.ipynb): Edit graph state using `graph.update_state` method. Use this if implementing a **human-in-the-loop** workflow via **static breakpoints**.
 - [How to add dynamic breakpoints with `NodeInterrupt`](human_in_the_loop/dynamic_breakpoints.ipynb): **Not recommended**: Use the [`interrupt` function](../concepts/human_in_the_loop.md) instead.
 
+### Time Travel
+
+[Time travel](../concepts/time-travel.md) allows you to replay past actions in your LangGraph application to explore alternative paths and debug issues. These how-to guides show how to use time travel in your graph.
+
+- [How to view and update past graph state](human_in_the_loop/time-travel.ipynb)
+
 ### Streaming
 
 [Streaming](../concepts/streaming.md) is crucial for enhancing the responsiveness of applications built on LLMs. By displaying output progressively, even before a complete response is ready, streaming significantly improves user experience (UX), particularly when dealing with the latency of LLMs.