add sicp1.2

Author: QiJun.Wei

README.md

@@ -5,5 +5,6 @@
 Some notes about code
 
 - [SICP中的编程技艺1.1](https://bencode.github.io/code/tree/?path=sicp-1-1.ipynb)
+- [SICP中的编程技艺1.2](https://bencode.github.io/code/tree/?path=sicp-1-2.ipynb)
 - [Functional Programming Style and Streams](https://bencode.github.io/code/notebooks/index.html?path=functional-and-stream.ipynb)
 - [From a Number Formatting Example to Function Composition](https://bencode.github.io/code/notebooks/index.html?path=format-number.ipynb)