[Snyk] Upgrade metalsmith-markdown from 1.2.0 to 1.3.0#5

Douhgn wants to merge 1 commit intomasterDouhgn/jsdoc.github.io:masterfrom

snyk-upgrade-b459bfdbb2ceba94e3f761e368372f21Douhgn/jsdoc.github.io:snyk-upgrade-b459bfdbb2ceba94e3f761e368372f21Copy head branch name to clipboard