Remove unnecessary whitespace

[goto-bus-stop]

Right now

bel`
  <div>
    Contents
  </div>
`

generates something like

_div = document.createElement('div'), _div.textContent = '\n    Contents\n  '

But since it's semantically the same as

bel`<div>Contents</div>`

It could generate

_div = document.createElement('div'), _div.textContent = 'Contents'

instead.