code: function splitTag(editor, node, cursor) {
  	const open = getText(editor, node.open);
  	const m = open.match(/(\s*\/)?>$/);
  	const start = node.open.end.translate([0, m ? -m[0].length : 0]);
  	editor.setTextInBufferRange(new Range(start, node.open.end), `></${node.name}>`);
  
  	if (cursor) {
  		cursor.setBufferPosition(start.translate([0, 1]));
  	}
  }
docs: Splits given unary (self-closing) tag into opening and closing tags
  @param  {TextEditor} editor
  @param  {Node}       node
  @param  {Cursor}     cursor