Man pages matching name markdent::dialect::github::blockparser in section 3pm:

Markdent::Dialect::GitHub::BlockParser.3pm.en	debian 10 / libmarkdent-perl
Markdent::Dialect::GitHub::BlockParser.3pm.en	debian 11 / libmarkdent-perl
Markdent::Dialect::GitHub::BlockParser.3pm.en	debian 12 / libmarkdent-perl