message: Add syntax highlighting for Lua
diff: @@ -228,6 +228,9 @@ const wchar_t* RE_RUBY_FORMAT = LR"(%(\d+\$)?[-+ #0]{0,5}(\d+|\*)?(\.(\d+|\*))?(
  // Qt and KDE formats
  const wchar_t* RE_QT_FORMAT = LR"(%L?(\d\d?|n))";
  +// Lua
  +const wchar_t* RE_LUA_FORMAT = LR"(%[- 0]*\d*(\.\d+)?[sqdiouXxAaEefGgc])";
  +
  } // anonymous namespace
  @@ -304,6 +307,11 @@ SyntaxHighlighterPtr SyntaxHighlighter::ForItem(const CatalogItem& item, int kin
  static auto qt_format = std::make_shared<RegexSyntaxHighlighter>(RE_QT_FORMAT, TextKind::Placeholder);
  all->Add(qt_format);
  }
  + else if (fmt == "lua")
  + {
  + static auto lua_format = std::make_shared<RegexSyntaxHighlighter>(RE_LUA_FORMAT, TextKind::Placeholder);
  + all->Add(lua_format);
  + }
  }
  // basic highlighting has highest priority, so should come last in the order:
  