Update README.md (#978)

### What problem does this PR solve?

_Briefly describe what this PR aims to solve. Include background context
that will help reviewers understand the purpose of the PR._

### Type of change

- [x] Documentation Update

README.md

@@ -27,19 +27,19 @@
 <details open>
 <summary></b>📕 Table of Contents</b></summary>
   
-- [💡 What is RAGFlow?](#what-is-ragflow)
-- [🎮 Demo](#demo)
-- [📌 Latest Updates](#latest-updates)
-- [🌟 Key Features](#key-features)
-- [🔎 System Architecture](#system-architecture)
-- [🎬 Get Started](#get-started)
-- [🔧 Configurations](#configurations)
-- [🛠️ Build from source](#build-from-source)
-- [🛠️ Launch service from source](#launch-service-from-source)
-- [📚 Documentation](#documentation)
-- [📜 Roadmap](#roadmap)
-- [🏄 Community](#community)
-- [🙌 Contributing](#contributing)
+- 💡 [What is RAGFlow?](#-what-is-ragflow)
+- 🎮 [Demo](#-demo)
+- 📌 [Latest Updates](#-latest-updates)
+- 🌟 [Key Features](#-key-features)
+- 🔎 [System Architecture](#-system-architecture)
+- 🎬 [Get Started](#-get-started)
+- 🔧 [Configurations](#-configurations)
+- 🛠️ [Build from source](#-build-from-source)
+- 🛠️ [Launch service from source](#-launch-service-from-source)
+- 📚 [Documentation](#-documentation)
+- 📜 [Roadmap](#-roadmap)
+- 🏄 [Community](#-community)
+- 🙌 [Contributing](#-contributing)
 
 </details>