Support for Markdown comments in mappings

[Juuxel]

Java 23 will be adding Markdown javadoc comments (JEP 467). They use a different comment style (///) compared to the traditional HTML comments (/** */), so they'll need special support across the toolchain.

• Support in mappings
  • mapping-io API for Markdown comments
    • CommentStyle enum with HTML and MARKDOWN?
  • Tiny format support
    • Might need Tiny 2.1
    • md instead of c?
  • Enigma format support
    • Example: MDCOMMENT instead of COMMENT
• Support in Enigma (the app, possibly also the old mapping reader/writer)
• Support in javapoet
• Support in decompilers for the new comment style
  • Especially Vineflower and Fabric's CFR and Fernflower forks
• Support in Loom
  • Essentially bridging all this together
• We could also try to convert the MD comments to HTML to support them early in decompilers etc
  • Converters: Pandoc or a Java library like flexmark or commonmark-java (the last one is used in the JDK for the conversion)
  • Needs to work with the extensions like GFM tables or javadoc tags