Replace XML-style markup tags in comments with markdown equivalents:
- <code>...</code> to `...` (inline code)
- <tt>...</tt> to `...` (teletype/monospace)
- <i>...</i> to *...* (italics/emphasis)
- +...+ to `...` (parameter/variable references)
Updated 80+ files across core source, headers, mrbgems, and libraries
to use consistent markdown formatting in documentation comments.
Handled edge cases including special characters like <=> operators.
Co-authored-by: Atlassian Rovo Dev
Yukihiro "Matz" Matsumoto