Is your feature request related to a problem? Please describe.
Add back Factory reset: clear all nvm + application + bootloader setting (leaving only bootloader + mbr + sd), this is still useful feature to troubleshoot user issue.
factory reset can be triggered by:
dedicated pin on boot with feather nrf52832 (need to specifically enabled)
magic number with DFU_MAGIC_FACTORY_RESET to activate from simple app/sketch
revert changes in 99d31d2c827154632e38c9f3abf636433036f815
Is your feature request related to a problem? Please describe.
DFU_MAGIC_FACTORY_RESETto activate from simple app/sketch