v3.1.0

🚀 Features

• Added a browser-compatible ESM bundle, and updated exports to use it.
• Added debugging option __extendSyntax, which defaults to the value of __flagN.
• Subroutines avoid adding anonymous captures for regexes that don't use backreferences.
• The token separator (?:) is added to emitted regex source in fewer cases.

🐞 Fixes

• Rewrote subroutine backreference handling for maintainability, and fixed some complex edge cases in the process.
• Avoids removing (?:) in edge cases when doing so would make an invalid regex valid.