build: bump parallel from 1.17.0 to 1.18.0 in /docs
build: bump parallel from 1.17.0 to 1.18.0 in /docs

Bumps [parallel](https://github.com/grosser/parallel) from 1.17.0 to 1.18.0.
- [Release notes](https://github.com/grosser/parallel/releases)
- [Commits](https://github.com/grosser/parallel/compare/v1.17.0...v1.18.0)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
mahori/brew,EricFromCanada/brew,reitermarkus/brew,mahori/brew,EricFromCanada/brew,MikeMcQuaid/brew,Homebrew/brew,claui/brew,sjackman/homebrew,konqui/brew,JCount/brew,vitorgalvao/brew,nandub/brew,Homebrew/brew,sjackman/homebrew,nandub/brew,konqui/brew,claui/brew,mahori/brew,nandub/brew,claui/brew,reitermarkus/brew,JCount/brew,Homebrew/brew,MikeMcQuaid/brew,JCount/brew,mahori/brew,vitorgalvao/brew,sjackman/homebrew,nandub/brew,Homebrew/brew,EricFromCanada/brew,claui/brew,konqui/brew,vitorgalvao/brew,MikeMcQuaid/brew,sjackman/homebrew,JCount/brew,EricFromCanada/brew,MikeMcQuaid/brew,reitermarkus/brew,vitorgalvao/brew,reitermarkus/brew,konqui/brew