Update Documentation and possible modernization

[My1]

while this still seems to work it certainly seems to have some flaws e.g. not seeing the sys partition prior to a program restart or some parts are outdated, like kezplez has been superseded and keys.txt is no longer a thing in favor of prod and title.keys.

or also if you need prodinfo anyway, do you really need to explicitly enter the rsa_kek if it's just loaded from that?