Add optional reasons to karma voting

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+ решение сработало
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- вопрос недостаточно конкретный
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The issue provides only positive and negative examples of possible voting reasons; it names no files, tests, or entry points. First determine where karma voting is implemented and clarify how optional reasons should be supplied, stored, and displayed; done should include the agreed behavior and tests for both examples.

Written by the indexing model from the issue text.