TUI - Onboarding - how to paste a key

Now, the information is on the first screen

How should be:
The information should be available for users when it is needed, so when they paste keys.

To be consider:
Maybe the info how to paste should be also available where a user pastes a password or path to file?

To be decided:
There are following solutions:

• info will be on the screen when users want to paste a key
• it will be in Help, but there should be info how to open a Help (like it is on the first screen)

@dan will rewrite the instruction.