added to benchmark list

docs/tools/bench.md

@@ -29,6 +29,7 @@ The current benchmarks are:
 * `gcd`: Calculate Greatest Common Divisor (GCD) of two input positive integer using [Euclidean algorithm][euclidean_into].
 * `loopfact`: Compute *n!* imperatively using a loop.
 * `mandelbrot`: Generates a really low resolution, ascii, [mandelbrot set][mandelbrot].
+* `matmul2x2`: Calculates a simple deterministic matrix multiplication of size 2x2.
 * `mat-inv` : Calculates the inverse of a 3x3 matrix and prints it out.
 * `mat-mul`: Multiplies two `nxn` matrices using the [naive][matmul] matrix multiplication algorithm. The matrices are randomly generated using a [linear congruential generator][rng].
 * `max-subarray`: solution to the classic Maximum Subarray problem.