docs: add mono0x as a contributor for code, and test

[allcontributors[bot]]

Adds @mono0x as a contributor for code, test.

This was requested by kentcdodds in this comment

[github-actions[bot]]

:tada: This PR is included in version 3.0.2 :tada:

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot :package::rocket: