Reorganized docs for docusaurus publish (#860)

### 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

docs/quickstart.md

@@ -1,4 +1,9 @@
-# Quickstart
+---
+sidebar_position: 1
+slug: /
+---
+
+# Quick start
 
 RAGFlow is an open-source RAG (Retrieval-Augmented Generation) engine based on deep document understanding. When integrated with LLMs, it is capable of providing truthful question-answering capabilities, backed by well-founded citations from various complex formatted data.
 
@@ -20,7 +25,7 @@ This quick start guide describes a general process from:
 
 ## Start up the server
 
-1. Ensure `vm.max_map_count` >= 262144 ([more](./docs/max_map_count.md)):
+1. Ensure `vm.max_map_count` >= 262144:
 
    > To check the value of `vm.max_map_count`:
    >