Bump loader-utils from 1.4.0 to 1.4.2 in /docs

Bumps [loader-utils](https://github.com/webpack/loader-utils) from 1.4.0 to 1.4.2.
- [Release notes](https://github.com/webpack/loader-utils/releases)
- [Changelog](https://github.com/webpack/loader-utils/blob/v1.4.2/CHANGELOG.md)
- [Commits](webpack/loader-utils@v1.4.0...v1.4.2)

---
updated-dependencies:
- dependency-name: loader-utils
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>