Description of the change

Now, instead of directly wrapping code inside HTML tags, the parser properly replaces any HTML-specific characters to avoid rendering issues. The function is implemented as inline std::string maddy::common::escapeHTML(const std::string& input)

Checklist for contributor

• if you want to be mentioned in the AUTHORS file, you added yourself
• added an entry to CHANGELOG.md at "Upcoming"
• if any Markdown definition changed, you updated the definition docs
• your C++ code change is accommodated with a unit/integration test where it makes sense
• your code meets the code format style (clang-format) of the project (tools/format.py)