Release version 2.2.0

• Add support version Redmine 4.0.

Release version 2.1.0

• Add simplified chinese.
  Thanks @archonwang .

Release version 2.0.0

• Add pop-up show feature on wiki's history diff.
• Change legend position.

Release version 1.0.1

• Fix a small bug.
• Add test version.
• Installation command change in readme.

Release version 1.0.0

• This plugin provide on pop-up show feature of diff.