docs: standardize Code of Conduct capitalization

[cruujon]

Description

This PR standardizes the capitalization of 'Code of Conduct' in the main heading and section heading to improve consistency with standard documentation practices.

Changes

• Capitalized 'Code of Conduct' in main heading
• Capitalized 'Code of Conduct' in section heading

Type of change

• Documentation improvement
• Typo fix

Testing

• Verified changes are consistent with standard documentation practices

This is a small documentation improvement that enhances consistency across the codebase.

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[wackerow]

Hey there @cruujon, which standard documentation practices? Ours reference using sentence casing for all headers

[wackerow]

Closing this one out