[Snyk] Upgrade @metalsmith/markdown from 1.6.0 to 1.9.1#215

NOUIY wants to merge 1 commit intomainNOUIY/nodejs.org:mainfrom

snyk-upgrade-0992a1d2f7c3a0077f53973ad91982fcNOUIY/nodejs.org:snyk-upgrade-0992a1d2f7c3a0077f53973ad91982fcCopy head branch name to clipboard