add markdown dialect (WIP) & add strikethrough and underline font styles

src/devtools/syntax_highlighting.hpp

@@ -6,6 +6,10 @@
 struct FontStylesScheme;
 
 namespace devtools {
+    enum SyntaxStyles {
+        DEFAULT, KEYWORD, LITERAL, COMMENT, ERROR
+    };
+
     std::unique_ptr<FontStylesScheme> syntax_highlight(
         const std::string& lang, std::string_view source
     );