docs: add DeepWiki developer guide page (#14244)

Closes #14165

Add a short documentation page under Developer Guides introducing
DeepWiki as a resource for developers doing secondary development or
exploring RAGFlow's codebase internals.

---------

Co-authored-by: hyl64 <hyl64@users.noreply.github.com>

docs/develop/deepwiki.md

@@ -0,0 +1,70 @@
+---
+sidebar_position: 1
+slug: /deepwiki
+sidebar_custom_props: {
+  categoryIcon: LucideBookOpen
+}
+---
+
+# Explore RAGFlow on DeepWiki
+
+An AI-generated, always-up-to-date knowledge base for understanding RAGFlow's codebase — designed for developers doing secondary development or deep-diving into RAGFlow's internals.
+
+---
+
+:::caution NOTE
+The RAGFlow content on DeepWiki is maintained by DeepWiki, not by the RAGFlow team. It may lag behind the latest official release. Always refer to the official [RAGFlow documentation](https://ragflow.io/docs/dev/) and [source code](https://github.com/infiniflow/ragflow) for the most up-to-date information.
+:::
+
+## What is DeepWiki?
+
+[DeepWiki](https://deepwiki.com) is an AI-powered tool that automatically reads a GitHub repository's source code, tests, and documentation to produce a structured, interactive wiki. It maps out architecture diagrams, module relationships, data flows, and design rationale — all without requiring manual documentation work.
+
+## The RAGFlow DeepWiki page
+
+The RAGFlow project is indexed at:
+
+**[https://deepwiki.com/infiniflow/ragflow](https://deepwiki.com/infiniflow/ragflow)**
+
+## Target audience
+
+This resource is primarily intended for:
+
+- **Secondary developers** who want to extend or customize RAGFlow (e.g., add a new document parser, integrate a new LLM provider, or modify the retrieval pipeline).
+- **Contributors** who need to understand how a specific module fits into the overall architecture before filing a PR.
+- **Researchers and engineers** who want to study RAGFlow's internal design principles — chunking strategies, embedding pipelines, graph-based retrieval, and agent orchestration.
+
+:::tip NOTE
+For general usage of RAGFlow (configuring knowledge bases, running chat, etc.), the [Guides](../guides/) section is a better starting point.
+:::
+
+## What you can find on DeepWiki
+
+| Topic | What to look for |
+|---|---|
+| **Overall architecture** | High-level component diagram showing how `api/`, `rag/`, `deepdoc/`, `agent/`, and `web/` relate to each other |
+| **Document ingestion pipeline** | How files flow from upload → parsing (`deepdoc/`) → chunking → embedding → storage |
+| **Retrieval pipeline** | How queries are processed, how hybrid search (keyword + vector) works, and how reranking is applied |
+| **Agent framework** | How `agent/` orchestrates multi-step reasoning, tool calling, and memory |
+| **LLM / Embedding abstractions** | How `rag/llm/` wraps different model providers behind a unified interface |
+| **API layer** | How `api/apps/` Blueprint routes map to internal service calls |
+
+## Using DeepWiki alongside local development
+
+When you are making changes to the codebase, DeepWiki can help you quickly answer questions such as:
+
+- *"Where is the entry point for task execution?"*
+- *"Which class handles PDF page segmentation?"*
+- *"How does the knowledge graph retrieval differ from the dense vector path?"*
+
+You can also ask DeepWiki questions in natural language using its built-in chat interface — it will ground its answers in the actual source code.
+
+## Keeping the wiki current
+
+DeepWiki re-indexes the repository automatically when the upstream `main` branch is updated. If you notice the indexed content lagging behind a recent release, you can trigger a manual re-index from the DeepWiki page.
+
+## Related resources
+
+- [Launch service from source](./launch_ragflow_from_source.md) — set up a local RAGFlow development environment.
+- [Build RAGFlow Docker image](./build_docker_image.mdx) — build a custom image after code changes.
+- [Contribution guidelines](./contributing.md) — how to file a PR once you understand the codebase.