RDoc escapes <sup> tags

The documenetation for the Regexp class in the standard library uses <sup> which is escaped as you can see here:

https://ruby-doc.org/core-3.0.1/Regexp.html#class-Regexp-label-Capturing

Parentheses can be used for capturing. The text enclosed by the n^th group of parentheses can be subsequently referred to with n. Within a pattern use the backreference \n; outside of the pattern use MatchData[n].

Can we allow <sup> tags? I believe that, in addition to HTML, some Markdown flavors support <sup> and <sub>. For example, GitHub lets me do this: regular ^superscript _subscript

Start by reproducing the escaping in the linked Regexp documentation and trace how RDoc handles the documented ^{tags. Check the related Markdown or HTML rendering path; done means supported superscript and subscript tags render as markup instead of appearing escaped in generated documentation.}