Furo: Add breadcrumb menu

[javabster]

In the existing qiskit.org/documentation pages we have a breadcrumb menu at the top of the page, which I think would be a good addition to the Furo theme. I personally find this very useful for navigation, checking file/import paths etc. , especially when I'm searching in the depths of the API reference

[Eric-Arellano]

I'm seeing if we can contribute this to upstream Furo: pradyunsg/furo#139 (reply in thread). Abby and I are thinking that proposed design meets Qiskit brand requirements - it's similar to IBM Cloud's docs:

[Eric-Arellano]

We decided with the design team (Russell, Jules, Randy, and Eddy) that breadcrumbs are a valuable feature. But it's not a blocker for Furo 1.0, including because the Furo left sidebar design already makes clear to the user where you are. This feature will be added post-Furo 1.0.

[coruscating]

Also, note that Experiments was using breadcrumbs for displaying the package version no matter which page you're on (from #266):

By default, the only place where versions are shown is the title of the page, but most users won't notice that. I thought a good solution before breadcrumbs return would be to add a link to the home page to the sidebar that contains the package name + version, but the sidebar renders variables literally:

We can override the sidebar but I'd rather not do something so hacky, so other ideas are welcome.

[Eric-Arellano]

@coruscating I think the best fix will be #483 from the Ecosystem theme. The text will include the project version number. It will always be present in the left side bar.

[coruscating]

@Eric-Arellano Yeah, I didn't realize the project name will also have the version. We're good then. Maybe it'll be good to discuss whether it's the version or release number that should be there (like 0.6 versus 0.6.2).

[Eric-Arellano]

Given that Furo makes visually clear via its left sidebar where you are—and the Qiskit Ecosystem theme shows in the top left corner the current docs version—I don't think there's much urgency to adding breadcrumbs.

It's definitely a nice to have! But I'll have much less time to work on this repo, so I'm trying to prioritize what work can realistically be done in Q3.

If anyone is interested in this feature, I'd still love to see it. The best approach is to add it to Furo directly, which Pradyun has said they'd like: pradyunsg/furo#139 (reply in thread)