document f3probe assumptions

My brief inspections of the code suggest that f3probe assumes sector wrapping with a modulus that is a power of 2. Is this correct? It would be great to add a sentence or two in the readme what type of fake drives it can detect and what its limitations are. For example, can it detect a 2 TB fake drive with a 320 GB internal disk where 512-byte sector indices are wrapped modulo 625000448?