2-4集合类型_初译未自校
初稿提交

翻译者校队中
已初步自校
已初步自校
Merge pull request #1 from CocoaChina-editors/master

合并CocoaChina-Editors的工程
Merge pull request #77 from Phenmod/master

2-4集合类型翻译完毕，已初步自校。
Update 01About Swift.md
翻译完成

翻译完成
Merge pull request #78 from Charles-Lau/patch-1

Update 01About Swift.md
Merge pull request #79 from sherlockdan/master

完成A.2-5翻译