Update README.md

Author: CC-bit

README.md

@@ -1,2 +1,22 @@
 # UCB-CS61A-Textbook
 The textbook of UCB-CS61A
+
+USB CS61A web textbook *Composing Programs*
+
+Original address: https://www.composingprograms.com/
+
+Original author: [John DeNero](http://www.denero.org/)
+
+This project is its epub ebook version, created by [EpubPressX](https://chromewebstore.google.com/detail/akgkfegkiajbamekmkcafnfckmhgcnpa?utm_source=item-share-cp) and [Calibre](https://calibre-ebook.com/)
+
+Same as the original project, this project is licensed under a [Creative Commons Attribution-ShareAlike 3.0 Unported License](http://creativecommons.org/licenses/by-sa/3.0/)
+
+USB CS61A网页版教材《Composing Programs》
+
+原地址：https://www.composingprograms.com/
+
+原作者：[John DeNero](http://www.denero.org/)
+
+本项目是其epub电子书版本，使用[EpubPressX](https://chromewebstore.google.com/detail/akgkfegkiajbamekmkcafnfckmhgcnpa?utm_source=item-share-cp) and [Calibre](https://calibre-ebook.com/)制作
+
+与原项目相同，本项目也使用[Creative Commons Attribution-ShareAlike 3.0 Unported License](http://creativecommons.org/licenses/by-sa/3.0/)