Recent Syntax Changes

[smores56]

We have recently created many issues surrounding new syntaxes being added to Roc. To collect these into a single, pinnable issue, this issue is now the representative for discoverability of all recent syntax issues.

• Add a return Keyword #7104
  • Add an if-return Guard Syntax #7105
• Improve Error Handling Ergonomics #7086
• Simplify Types with .. Spread Syntax #7091
• Remove wildcard * type variables #7451
• Add new ... ellipsis keyword #7440

[gamebox]

Do we want to put things like snake_case, PNC, and new lambda syntax here? (even though they are done?)

[smores56]

If they have GitHub issues, they should go in here. If they don't have issues and they're finished already, don't bother creating issues.