Build(deps): Bump body-parser and express in /docs

Bumps [body-parser](https://github.com/expressjs/body-parser) and [express](https://github.com/expressjs/express). These dependencies needed to be updated together.

Updates `body-parser` from 1.20.1 to 1.20.3
- [Release notes](https://github.com/expressjs/body-parser/releases)
- [Changelog](https://github.com/expressjs/body-parser/blob/master/HISTORY.md)
- [Commits](expressjs/body-parser@1.20.1...1.20.3)

Updates `express` from 4.18.2 to 4.21.0
- [Release notes](https://github.com/expressjs/express/releases)
- [Changelog](https://github.com/expressjs/express/blob/4.21.0/History.md)
- [Commits](expressjs/express@4.18.2...4.21.0)

---
updated-dependencies:
- dependency-name: body-parser
  dependency-type: indirect
- dependency-name: express
  dependency-type: indirect
...

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

Author: dependabot[bot]