(set-clue clue-record [pair or key]) -> one or more clue records, or null
Modifies the given clue-record with the given pair or key value. If the clue-record is not found, null is returned. If more than one record matches, all that match are modified.
Examples:
>> (set-clue (find-clue db (last-name "Jones")) (first-name "Abrham")) :: ([clue-record [vector ...]])
>> (set-clue (find-clue db (last-name "Doe")) (address "21 Main Street")) :: ([clue-record [vector ...]] [clue-record [vector ...]])