v2.9.0

What's Changed

• Add space-dash rule to add space between -, default: off.

  - 你好-世界
  + 你好 - 世界

• Add space-backticks rule, default: on

  - 演示`code`代码
  + 演示 `code` 代码

• Add Aho-Corasick algorithm for spellcheck backend to match keywords. (#171)

• Improve format and lint method for performance up ~20%.