Man pages matching name markdown in section 3:

markdown.3.en	debian 10 / libmarkdown2-dev
Markdown.3.en	debian 10 / markdown
markdown.3.en	debian 11 / libmarkdown2-dev
Markdown.3.en	debian 11 / markdown
markdown.3.en	debian 12 / libmarkdown2-dev
Markdown.3.en	debian 12 / markdown