docs: Arxiv docs update (#23871)
- [X] **PR title**
- [X] **PR message**: ***Delete this entire checklist*** and replace
with
- **Description:** Update of docstrings and docpages
- **Issue:**
[22866](https://github.com/langchain-ai/langchain/issues/22866)
- [X] **Add tests and docs**
- [X] **Lint and test**
