Autoresize Demo自动改变尺寸演示文档

By setting an editor's height style to auto and giving the viewportMargin a value of Infinity, CodeMirror can be made to automatically resize to fit its content.通过把编辑器的height样式设置为auto，并给viewportMargin设定值为Infinity，CodeMirror可变成自动调整尺寸以适应它的内容。