This file contains the basic hardware configuration of your keyboard. It will contain at the minimum these 5 lines:
Other lines can be added for other features like battery monitoring, RGB Underglow, Backlight LEDs and other hardware features that are connected to the microcontroller. For more information on the options available to add in hardware_config.h refer here
This file contains the basic firmware configuration of your keyboard. It will contain at the minimum these 4 lines and a KEYMAP macro definition:
If you have a split keyboard, you will also need to define the name of the left and right halves.
The most basic keymap.h file will need the following two lines to declare the matrix of keys and a function to map keycodes to the keys.
The most basic keymap.cpp file will define what we declared above.