Set `height` in `ploty_ly` and use `height = "auto"` in `plotlyOutput`

Hello,

In the doc of plotlyOutput, the usage of height="auto" is not encouraged. However using height="auto" in plotlyOutput and setting height in the plot_ly function gives a perfect result, and this is very useful to have the ability to set the height in the plot_ly function. So I think this "trick" should be mentioned in the doc.

找出 plotlyOutput 文件及其目前對 height="auto" 的說明，接著檢視 plot_ly 文件中對 height 引數的說明。更新文件，描述如何在 plotlyOutput 中使用 height="auto"，並在 plot_ly 中設定 height，然後確認轉譯後的文字是否清楚說明這種用法。