see #12: add chapter sketch

book/en-us/00-preface.md

@@ -0,0 +1,23 @@
+---
+title: Preface
+type: book-en-us
+order: 0
+---
+
+# Preface
+
+[TOC]
+
+## Introduction
+
+## Targets
+
+## Purpose
+
+## Code
+
+[Table of Content](./toc.md) | [Next Chapter: Towards Modern C++](./01-intro.md)
+
+## Licenses
+
+<a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/"><img alt="Creative Commons License" style="border-width:0" src="https://i.creativecommons.org/l/by-nc-nd/4.0/88x31.png" /></a><br />This work was written by [Ou Changkun](https://changkun.de) and licensed under a <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License</a>. The code of this repository is open sourced under the [MIT license](../../LICENSE).