gitbook/docs/structure.md

Directory structure

.
├── book.json
├── README.md
├── SUMMARY.md
├── chapter-1/
|   ├── README.md
|   └── something.md
└── chapter-2/
    ├── README.md
    └── something.md

An overview of what each of these does:

File	Description
book.json	Stores configuration data (optional)
README.md	Preface / Introduction for your book (required)
SUMMARY.md	Table of Contents

Sub-directory