v3.9.0

• A new shellQuote function was added to the template system ({{shellQuote "a string"}}) to ensure a string is safe for use in shell (mvdan/sh#727, mvdan/sh#737, Documentation)
• In this version mvdan.cc/sh was upgraded with some small fixes and features
  • The read -p flag is now supported (#314, mvdan/sh#551, mvdan/sh#772)
  • The pwd -P and pwd -L flags are now supported (#553, mvdan/sh#724, mvdan/sh#728)
  • The $GID environment variable is now correctly being set (#561, mvdan/sh#723)