Fix package-lock.json

There was a bug in an earlier version of `npm@7`
that causes some information about bins and
engines to be lost when upgrading from lock file
version 1 to 2, as was done in 0d1e40b.

See npm/cli#1957

This has since been fixed with npm/arborist@a49d3fb

This commit contains the regenerated lockfile
from before 0d1e40b,
which has been fixed with `npm@7.3.0`, using the
instructions at npm/cli#1957 (comment)

Additionally, `markdownlint-cli` is removed, which
should have been done in 0d1e40b