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

src/graphics/ui/markdown.hpp

@@ -0,0 +1,22 @@
+#pragma once
+
+#include <string>
+#include <memory>
+
+struct FontStylesScheme;
+
+// VoxelCore Markdown dialect
+
+namespace markdown {
+
+    template <typename CharT>
+    struct Result {
+        /// @brief Text with erased markdown
+        std::basic_string<CharT> text;
+        /// @brief Text styles scheme
+        std::unique_ptr<FontStylesScheme> styles;
+    };
+
+    Result<char> process(std::string_view source, bool eraseMarkdown);
+    Result<wchar_t> process(std::wstring_view source, bool eraseMarkdown);
+}