Provide a link to the px reference page on every chart page

[chriddyp]

We currently link to the graph objects reference page, but not to the px sunburst page.

[emmanuelle]

For interested contributors, the px reference page is https://plotly.com/python-api-reference/plotly.express.html. Please read the Readme in https://github.com/plotly/plotly.py/tree/master/doc to learn how the doc is organized and edited.

[ry-v1]

@chriddyp @emmanuelle - I can work on this, can you please assign it to me.
Is the below format is fine.

Reference
See https://plotly.com/python/reference/sunburst/ or https://plotly.com/python-api-reference/generated/plotly.express.sunburst.html for more information and chart attribute options!

I do see px site doesn't have documentation for all the charts like bubble, bullet and candlestick chart.

[emmanuelle]

Assigned! Yes, plotly.express does not have (yet) functions for all traces. You can find the list of available functions in https://plotly.com/python-api-reference/plotly.express.html.

For the format it looks good, just put the plotly.express link first please.

[ry-v1]

Sure, will do

[nicolaskruchten]

For the PX link it might be nice to have some link text like "function reference for px.scatter()" instead of that big URL?

[ry-v1]

How about this?

Reference
See function reference for px.sunburst() or https://plotly.com/python/reference/sunburst/ for more information and chart attribute options!

[nicolaskruchten]

I would use something like this:

See function reference for px.sunburst() or ...

with the following code:

See [function reference for `px.sunburst()`](https://plotly.com/python-api-reference/generated/plotly.express.sunburst) or ...

[ry-v1]

I have submitted pull request #2784. Please check.