Examples improvement: highlight with/without `connectivity` in unstructured examples

[trexfeathers]

📚 Documentation

Half the unstructured examples don't use the connectivity= parameter in Transform.from_unstructured(), while the other half do. Something different is clearly happening under the hood, but it is not obvious what (in fact I need to do some investigating before I understand it!). I think it would be good to highlight the difference within the relevant examples.

• Here is one without: DYNAMICO Mesh — GeoVista 0.5.0.dev339 documentation
• Here is one with: LFRic Mesh — GeoVista 0.5.0.dev339 documentation

Happy to have a go at this if I can make the time.

[bjlittle]

My aim was to keep the gallery examples informative to showcase specific features, but simple i.e., not bloat the narrative with any deeper explanations.

Instead, there will be places in the geovista documentation where a fuller treatment and explanation of the how, what and why e.g., either through the tutorials, how-to guides or enrichment material.

Once the supporting documentation is available, then I think it would be ideal to link to the relevant material from the gallery examples.

Does that seem like a reasonable approach?