Merge pull request #44 from andelf/master

add claim date
Create After.md
Update After.md
Update After.md
Update After.md
Update After.md
Update After.md
Create Sleep.md
Update Sleep.md
Update After.md
Update After.md
Create Tick.md
Update Tick.md
Update Tick.md
Create ParseDuration.md
begin encoding/base32
mark date
Merge pull request #45 from boilingbit/master

认领 encoding/base32
Merge pull request #46 from Unknwon/master

标记完成日期
Create FormatDoc.md

新建 FormatDoc.md,主要说明 format 格式中的相关要求。