Bump metalsmith from 2.5.1 to 2.6.2

Bumps [metalsmith](https://github.com/metalsmith/metalsmith) from 2.5.1 to 2.6.2.
- [Release notes](https://github.com/metalsmith/metalsmith/releases)
- [Changelog](https://github.com/metalsmith/metalsmith/blob/master/CHANGELOG.md)
- [Commits](metalsmith/metalsmith@v2.5.1...v2.6.2)

---
updated-dependencies:
- dependency-name: metalsmith
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]