Nethsm documentation corrections and additions

Various grammar and spelling corrections.
Various formulation improvements.
Correct header level.
Add a visualization for states and their transitions.
Alignments of nitropy options with nitropy tool --help output.
Rename HTTPS API to TLS interface and HTTPS certificate to TLS certificate.
Change order of states and boot mode chapters.
Adjust Docker command to current implementation.

Nitrokey / nitrokey-documentation