chore: bump globals from 13.20.0 to 13.21.0 (docsifyjs#2180)

Bumps [globals](https://github.com/sindresorhus/globals) from 13.20.0 to 13.21.0.
- [Release notes](https://github.com/sindresorhus/globals/releases)
- [Commits](sindresorhus/globals@v13.20.0...v13.21.0)

---
updated-dependencies:
- dependency-name: globals
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Koy Zhuang<[email protected]>

Author: dependabot[bot]