Bump axios and browser-sync in /docs

Removes [axios](https://github.com/axios/axios). It's no longer used after updating ancestor dependency [browser-sync](https://github.com/BrowserSync/browser-sync). These dependencies need to be updated together.


Removes `axios`

Updates `browser-sync` from 2.29.3 to 3.0.2
- [Release notes](https://github.com/BrowserSync/browser-sync/releases)
- [Changelog](https://github.com/BrowserSync/browser-sync/blob/master/CHANGELOG.md)
- [Commits](BrowserSync/browser-sync@v2.29.3...v3.0.2)

---
updated-dependencies:
- dependency-name: axios
  dependency-type: indirect
- dependency-name: browser-sync
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>