docs: fix typo 'contibuting' -> 'contributing' in CONTRIBUTING.mdx

[haosenwang1018]

Fixes a small typo in the documentation where 'contributing' was misspelled as 'contibuting'.

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Summary by cubic

Corrects a typo in docs/CONTRIBUTING.mdx. Replaces "contibuting" with "contributing" to improve clarity.

^{Written for commit 641c3fc. Summary will update on new commits.}

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[cubic-dev-ai]

No issues found across 1 file

[RomneyDa]

@haosenwang1018 thanks for the contribution. This is not needed for now.