I'd like to see something like this, couldn't figure out how to save generated keys in GPG or KBX formats... ```ruby # generate both a primary key and a subkey generated = rnp.generate_key( primary: { type: 'RSA, length: 2048, userid: 'testuser', usage: [:sign] }, sub: { type: 'RSA, length: 2048, usage: [:encrypt] } ) # save?? ```