vue 点击复制选中指定文本，超好用

经过测试，方法兼容谷歌和IE，提取成公共方法如下：

export function copyText(e) {
	let text = document.getElementById(e);
	let selection = window.getSelection();
	let range = document.createRange();
	range.selectNodeContents(text);
	selection.removeAllRanges();
	selection.addRange(range);
	document.execCommand("Copy")
}