* Update C syntax with keywords up to C23.
* Update C syntax with some GCC extensions.
* Update C# syntax with new keywords up to C# 12.
* Update C# syntax with preprocessor directives.
* Add Cake build script (C#) syntax.
* Add MSBuild (XML) syntax.
* highlighter: Fix region & pattern detection
* syntax/sh: Highlight upper case options too
* syntax/c(pp): Try to synchronize the rules to lower the maintenance effort
* syntax/ruby: Fix explicit filename detection in directories
* highlighter: Respect skip rules in regions
* syntax/sh: Fix parameter expansion, cond. flags and generalize filename via ""
* syntax/php|vi: Correct strings in comments to comments only
Additionally improve vimscript comment handling.
* highlighter: Remove problematic start|end check in find(all)Index()
...and additionally remove recursive region end detection
* Added highlighting for user-defined types
Provides automatic highlighting of user-defined types ending with either "_t" or "_T", as is seen in editors such as Nano, or within GitHub itself.
* Update cpp.yaml
Use the 'regexp2' library for lookahead and lookbehind in region
start and end regular expressions to support things like closing quotes
that aren't preceded by backslashes.
