(vector-set! vector integer value) -> #f
Destructively replaces the given index of vector with value.
Example:
>> (vector "a" "z" "c" "d")
:: #("a" "z" "c" "d")
>> (define a (vector "a" "z" "c" "d"))
:: #f
>> a
:: #("a" "z" "c" "d")
>> (vector-set! a 1 "b")
:: #f
>> a
:: #("a" "b" "c" "d")