WIP: fixup! Add documentation regarding Netboot
- Add note about Turris 1.x routers that there you need to setup /srv via Storage plguin
- Advanced configuration: you don't need to boot from Omnia, but from other MOX or Turris
- Some typos and I don't like word "inject additional files" what about just "add files"?
- Mention in canceling pairing that unpairing in Foris is not enough. Will it be enough "will reset U-boot settings"?