docs: Remove code style reference from CONTRIBUTING

[mtrezza]

New Pull Request Checklist

• [x] I am not disclosing a vulnerability.
• [x] I am creating this PR in reference to an issue.

Issue Description

Remove code style reference from CONTRIBUTING guide.

Closes: #n/a

[parse-github-assistant[bot]]

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[parseplatformorg]

🎉 This change has been released in version 2.0.3