Mention extra tag in hovertemplate tutorial

[emmanuelle]

Following various interactions on the forum, including https://community.plotly.com/t/tooltip-in-dash-shows-trace-0-how-to-get-rid-of-that/36844/2

[nicolaskruchten]

Thanks!

There's another way to control this, which is to set the hoverlabel.namelength attribute to 0 (to hide the name) or some big number (to show the whole name if it's long).

You could also mention that "anything goes" in the <extra></extra> it just happens to default to %{name} basically but you can put anything you like in there.

[emmanuelle]

thanks for the ideas I will integrate them. Regarding the chart studio problem has this been fixed in master or is it something new?

[nicolaskruchten]

I think it's fixed in master... let's ignore it for now

[emmanuelle]

Turns out hoverlabel.namelength is not used when a hovertemplate is used, so there was no good place to fit this in, and I was not sure it was worth a whole example. Can I merge this one?

[nicolaskruchten]

Does this conflict with the changes in your hover-data PR?

[emmanuelle]

Hum probably thanks for noticing this (but the conflict should be easy to fix). So either we merge now into doc-prod and I take care of conflicts when merging doc-prod into master just after, or we wait post-release to merge this PR after master has been merged into doc-prod, and I fix conflicts within the PR. Both solutions are fine with me.

[nicolaskruchten]

💃 to merge into doc-prod now, and if you have some time to merge doc-prod into master and resolve conflicts, that'd be great :)

[emmanuelle]

done, there was indeed a small merge conflict. I've pushed to master after merging doc-prod.