Add Documentation for the Used Cryptographic Algorithms

[FlorianWendelborn]

For projects like this, it is insanely important to disclose how exactly the encryption algorithm works.

The used algorithm should at least be mentioned in the Readme, but ideally there should be another "more detailed" explanation about how and why these algorithms are used.

[jaydenwindle]

Good idea 👍

I'll update the README with more detailed information about the algorithm used + the reasoning behind it as soon as I can.