Keyboard chord names

vm.send_keys(chord) takes --separated, case-insensitive QMP key names with aliases:

ctrl alt shift win/super/meta enter/return esc del space tab backspace
up down left right home end pgup/pageup pgdn/pagedown insert menu print
pause caps_lock num_lock scroll_lock f1..f12 a-z 0-9

Examples: "ctrl-alt-del", "enter", "shift-f5". vm.type_text is US-ASCII only (\n→enter, \t→tab).