Inclusive language in readme about bugszero-kata

[martinsson]

Thanks for noting! I like the first and the third alternatives. Feel free to PR, otherwise I hope I'll get to it Friday

[martinsson]

Awesome to use the spirit :)

[dertseha]

Pull request created.

I've opted for the complete-plural version (first one), since the third one, in the complete sentence, could have been interpreted as "You'll practice ... by extending the code.". i.e., the person that wants to practice would be practicing by extending the code. And the most likely necessary comma would be too small to make the difference.
Now it's "one person practicing" and "many people making bugs when extending code".

Thank you for the opportunity to contribute!