Add debugging documentation

[NiQ1]

Please add some sort of documentation of which debuggers are compatible PSL1GHT applications, and what are the requirements (I assume a DEX console would be required).
Currently the only mention of debugging is using stdout prints.

If there is no possible way of debugging properly without using leaked tools (i.e. ProDG) or it is not possible at all, I think this should be mentioned explicitly so developers don't spend time looking for something that doesn't exist.