Added 3x3 capability

Currently, the script uses the recursive method for calculating a
determinant of a square matrix, up to dimension 3x3. Each calculation
leading back to the 2x2 matix is determined by an if/else sort function
leading to the proper determinant calculating function. Next, I need to
consider if the calculation may be generalized to skip this step using :
"det A = n, j = 1 SUM (-1)^(1+j) a1j det A1j "