docs: update Markdown equation elements

[stdlib-bot]

This PR

• updates equation elements found in Markdown files

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
math/base/special/cexpf	$\\color{green}200/200$ $\\color{green}+100.00\\%$	$\\color{green}16/16$ $\\color{green}+100.00\\%$	$\\color{green}2/2$ $\\color{green}+100.00\\%$	$\\color{green}200/200$ $\\color{green}+100.00\\%$

The above coverage report was generated for the changes in this PR.