sci-pi.org.uk changes

24th July 2020: added page on memory latency of Pi and Core2.

10th July 2020: added comparison of Pi and Cray using Mersenne test, and rearranged the menu items for the pages relating to primes.

27th June 2020: added negative numbers and subtraction to from Transistors to a CPU.

11th June 2020: added an optimised Mandelbrot Set.

1st June 2020: site made known to Google, with 34 pages in sitemap.