functions: dwm style and more dwm-like names
treat startup command as long-running
Not quite a perfect mirror of xinit, where the startup command execs the
window manager, and the termination of that process brings down the
windowing system, but it might be the Wayland analogue.
implement Button: movemouse, resizemouse
make Makefile a bit more my style
make key mappings configurable in config.h
start factoring Key actions into functions
Start with tinywl
Add a config.h into which configurables can be moved.