Update free-programming-books-zh.md

added a few more Chinese resources:
   - The Little MongoDB Book 中文版
   - 文章《Functional Programming For The Rest of Us》的中文翻译
Add Operating Systems book
Add Wizard Code book
Merge pull request #557 from JIghtuse/master

Add two books on OS and low-level programming
Merge pull request #556 from justinyhuang/patch-1

Update free-programming-books-zh.md