Merge pull request #212 from ios8/gh-pages

病句勘误
update advanced operators

删除两句英文
Merge pull request #213 from yulingtianxia/gh-pages

update advanced operators
update advanced operators

删除英文
update advanced operators

删除英文
Merge branch 'gh-pages' of https://github.com/yulingtianxia/the-swift-programming-language-in-chinese into gh-pages
Merge pull request #214 from yulingtianxia/gh-pages

update advanced operators
add contributing file
Merge pull request #215 from yankuangshi/develop

add contributing file
make gitbook