Promote CRoCS's NIST STS, which is used in RTT

[Bender250]

From Lubo's thesis:

The reference implementation described in [9] is not used in RTT because it is con-
siderably slower than its optimized counterparts. The faster implementation used in RTT,
called NIST STS optimised v5.0.2, was developed by Marek Sýs and Zdeněk Říha [10].

Write about it on the index page:

Randomness Testing Toolkit
This service allows users to easily and quickly test randomness of their binary data. The data are analysed with following statistical software.

NIST Statistical Test Suite - note faster implementation here
Dieharder
TestU01