Ternary Contour Plots in JavaScript

I would like to reopen #3503.

Currently there is no native support of ploting contours in ternary plot, the current official documentation for it is wrong (or inconsistent). As reported in this issue from the graphing-library-docs repo.

In plotly.py, Ternary contours in Python, there are ternary contour plots examples:

But in JS, Contour Plots in JavaScript, we only get:

Apparently, the JS example only fills the area instead of doing what is expected of a "contour" plot.

It would be great if this could be implemented (or if it already is, but only requires data transformation? ) and if there were examples showing how to plot the contours as in Ternary contours in Python.

先查看链接的 JavaScript ternary-contour 和 contour-plots 文档，然后将其与链接的 Python ternary-contour 示例进行比较。确定 Plotly.js 是否已经支持所请求的渲染，还是需要实现和添加示例；完成的标准是 JavaScript 可以生成与 Python 示例相当的等高线，并且官方文档是正确的。