Adds examples for next Plotly.js version 3.1.0.

Merge after main branch has been updated to use Plotly.js 3.1.0

Documentation PR

• I have seen the doc/README.md file.
• This change runs in the current version of Plotly on PyPI and targets the doc-prod branch OR it targets the main branch.
• If this PR modifies the first example in a page or adds a new one, it is a px example if at all possible.
• Every new/modified example has a descriptive title and motivating sentence or paragraph.
• Every new/modified example is independently runnable.
• 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.
• Meaningful/relatable datasets are used for all new examples instead of randomly-generated data where possible.
• The random seed is set if using randomly-generated data.
• New/modified remote datasets are loaded from https://plotly.github.io/datasets and added to https://github.com/plotly/datasets.
• Large computations are avoided in the new/modified examples in favour of loading remote datasets that represent the output of such computations.
• Imports are plotly.graph_objects as go, plotly.express as px, and/or plotly.io as pio.
• Data frames are always called df.
• fig = <something> is called high up in each new/modified example (either px.<something> or make_subplots or go.Figure).
• Liberal use is made of fig.add_* and fig.update_* rather than go.Figure(data=..., layout=...).
• Specific adders and updaters like fig.add_shape and fig.update_xaxes are used instead of big fig.update_layout calls.
• fig.show() is at the end of each example.
• plotly.plot() and plotly.iplot() are not used in any example.
• Named colors are used instead of hex codes wherever possible.
• Code blocks are marked with ```python.