Update gems
Merge branch 'update-gems'
Update gems
Merge branch 'update-gems'
Set itemscope attribute to true
Merge branch 'use-boolean-attributes'
Use https
Tweak
Modify comment
Merge branch 'tweak'
Update gems
Merge branch 'update-gems'
Modify background color of 'pre' elements
Merge branch 'modify-bgcolor-of-pre'