Takes in a keypress/keydown/keyup event and returns a chord string. E.g. ctrl+shift+t
$ npm install @f/keychord
var keychord = require('@f/keychord')
function render () {
  return <div onKeypress={handleKeypress} />
}
function handleKeypress (e) {
  switch (keychord(e)) {
    case 'enter':
      // handle enter
      break
    case 'shift+enter':
      // handle shift+enter
      break
    case 'ctrl+up':
      // handle ctrl+up
      break
  }
}event- A (https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent)[KeyboardEvent] as in keypress/keyup/keydown.
Returns: A keychord string. If only one key is being pressed, just returns the name of that key. If it is a sequence of keys, returns a string of the form 'ctrl+shift+enter'.
MIT