add swarm plot to the scatter documentation

[rl-utility-man]

This is inspired by #5087. Many thanks to @suterberg for inspiring it and getting me started.

If your PR modifies code of the plotly package, we have a different checklist
below :-).

Documentation PR

• [ Y] I've seen the doc/README.md file
• [ Y] This change runs in the current version of Plotly on PyPI and targets the doc-prod branch OR it targets the main branch
• [ N/A] If this PR modifies the first example in a page or adds a new one, it is a px example if at all possible
• [ Y] Every new/modified example has a descriptive title and motivating sentence or paragraph
• [ Y] Every new/modified example is independently runnable
• [ Y] Every new/modified example is optimized for short line count and focuses on the Plotly/visualization-related aspects of the example rather than the computation required to produce the data being visualized
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• [ N/A] The random seed is set if using randomly-generated data in new/modified examples
• [ Y] New/modified remote datasets are loaded from https://plotly.github.io/datasets and added to https://github.com/plotly/datasets
• [ Y] Large computations are avoided in the new/modified examples in favour of loading remote datasets that represent the output of such computations
• [ Y ] Imports are plotly.graph_objects as go / plotly.express as px / plotly.io as pio
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• [ it's as high as it can logically go ] fig = <something> call is high up in each new/modified example (either px.<something> or make_subplots or go.Figure)
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[rl-utility-man]

I need to develop logic to "look left", spot any overlapping markers and increment the bin size potentially repeatedly if needed to avoid collisions.

[LiamConnors]

Is the print statement here intentional?

This currently appears above the graph

[rl-utility-man]

Thanks for catching that debugging leftover! Removed.

[LiamConnors]

Could we give the figure a title?

[rl-utility-man]

Good suggestion. Done!