docs: enhance why coderabbit page (#182)

* docs: enhance why coderabbit page

* docs: enhance why coderabbit page

* Update docs/overview/why-coderabbit.md

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

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Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>
Co-authored-by: alexcoderabbitai <[email protected]>