Fezzant's Tada68 keymap

Includes easy copy-paste macro creation for strings or combo keypresses.

• Layer 0: Mostly-standard base layer, with home/end replacing pgup/pgdn.
• Layer 1: Momentary function layer, with some added buttons.
• Layer 2: Toggle numpad layer, with a layout conducive to spreadsheets and calculations
• Layer 3: Momentary function layer to put backspace on spacebar, with arrow keys on right hand homerow area.