Create chap1.md
+ split chapter 1 file into 1.md and 1.1md and so on; add .gitignore
dded atom into glossary
add chapter 2
dded atom into glossary
Merge branch 'master' of https://github.com/MathCraft/shifrin-mathematica-book-zh_CN
Merge branch 'master' of https://github.com/MathCraft/shifrin-mathematica-book-zh_CN
Merge branch 'master' of https://github.com/MathCraft/shifrin-mathematica-book-zh_CN
Merge branch 'master' of https://github.com/MathCraft/shifrin-mathematica-book-zh_CN
Merge branch 'master' of https://github.com/MathCraft/shifrin-mathematica-book-zh_CN