Bump react-native from 0.63.4 to 0.64.0 in /website

Bumps [react-native](https://github.com/facebook/react-native) from 0.63.4 to 0.64.0.
- [Release notes](https://github.com/facebook/react-native/releases)
- [Changelog](https://github.com/facebook/react-native/blob/master/Releases.md)
- [Commits](facebook/react-native@v0.63.4...v0.64.0)

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