[Keyboard] Add dumbpad (#6425)

[Keyboard] Add dumbpad (#6425)

* removed some debug prints

* removed unnecessary files, tweaked some things

* rotary encoder button now connected into column 0, row 3

* tweaked keymap and moved encoder control into keymap

* tweaks

* added test keymap

* updated some things to make it easier to work with QMK configurator

* updates after merging latest master in

* fixed a few things

* removed test keymap and all related #ifdefs

* changed some dumbpad default keys, added KC_LOCK

* added image to readme

* added link to PCB github repo

* moved lock key to the rotary encoder pushbutton

* making suggested changes from @fauxpark in https://github.com/qmk/qmk_firmware/pull/6452

* adding bootmagic lite since i'm lazy and haven't soldered on the reset button...

* renamed  to

* using 7 underscores for KC_TRNS