update md for compile books for pdf and epub
Merge pull request #123 from Andrwyw/patch-7

Update memory.md
Merge pull request #126 from Andrwyw/patch-9

Update receive.md
Merge pull request #122 from Andrwyw/patch-6

Update index.md 为out-of-the-box添加解释（可直接使用、无需配置）
修正部分格式
修正部分格式翻译链接
Merge branch 'master' of https://github.com/Lin-H/android-training-course-in-chinese