build(deps): bump parallel from 1.20.1 to 1.21.0 in /docs
build(deps): bump parallel from 1.20.1 to 1.21.0 in /docs

Bumps [parallel](https://github.com/grosser/parallel) from 1.20.1 to 1.21.0.
- [Release notes](https://github.com/grosser/parallel/releases)
- [Commits](https://github.com/grosser/parallel/compare/v1.20.1...v1.21.0)

---
updated-dependencies:
- dependency-name: parallel
  dependency-type: indirect
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
EricFromCanada/brew,EricFromCanada/brew,nandub/brew,MikeMcQuaid/brew,MikeMcQuaid/brew,Homebrew/brew,JCount/brew,Homebrew/brew,EricFromCanada/brew,MikeMcQuaid/brew,Homebrew/brew,JCount/brew,nandub/brew,JCount/brew,MikeMcQuaid/brew,nandub/brew,Homebrew/brew,EricFromCanada/brew,nandub/brew,JCount/brew