feat: Strassen's matrix multiplication algorithm added

Author: sourav-625

matrix/strassen_matrix_multiply.py

@@ -193,5 +193,5 @@ def _strassen_recursive(matrix_a: Matrix, matrix_b: Matrix, threshold: int) -> M
         print(row)
 
     expected = naive_mul(A, B)
-    assert C == expected, "Strassen result differs from naive multiplication!"
+    assert expected == C, "Strassen result differs from naive multiplication!"
     print("Verified: result matches naive multiplication.")