manual steps for the max3 with the bltouch: https://github.com/billkenney/update_max3_plus3/blob/main/max3-bltouch.md
manual steps for the max3 with the inductive probe: https://github.com/billkenney/update_max3_plus3/blob/main/max3-probe.md
manual steps for the plus3: https://github.com/billkenney/update_max3_plus3/blob/main/plus3.md