Syntax highlighter doesn't support multi-line string literals

[nummacway]

Using valid multi-line string literals gives incorrect highlighting:

[Rangi42]

Added to gbdev/rgbds#1751

[nummacway]

Is there a list of features that you define as "new" in this context? For example, does it include explicit precision for fixed-point literals? Because rgbds-live's syntax highlighter also fails with that.