reference to Rabin-Karp
README: how to compile the benchmark script
README: typography
Merge pull request #3 from taleinat/master

Two small optimizations
optimisation comment
Keep just the sums' difference instead of two sums

The implementation is equivalent to initializing sum_diff to -needle_sum, then adding haystack_sum and checking if it is equal to zero.
Merge branch 'taleinat-patch-1'
Readme: new optimisation from 800888663848c4937f6cac9e5adc52166a2a6833
optimisation: check the first character before calling memcmp
optimisation: doesn't dereference two times the first character of needle
readme: typography