Visualization of the plotly.py project's codebase

[ivanmilevtues]

Hey I am leaving the documentation PR list, even though it is not exactly fitting there.
I usually create a discussion before such PR, but as you don't have the discussions enabled I decided to open a PR (feel free to close it).

Hi! This PR adds high-level diagrams of the plotly.py codebase to help new contributors quickly get oriented:
https://github.com/CodeBoarding/GeneratedOnBoardings/blob/main/plotly.py/on_boarding.md

The idea is to make onboarding easier—especially for open-source contributors who typically want to work on a specific module. Visualizing the codebase helps people understand how things fit together without needing to read everything up front.

We’ve also released a free GitHub Action that keeps the diagrams automatically updated as the code changes, so there's no ongoing maintenance burden.

I’d love to hear how you currently onboard new contributors—do you think something like this could help?
Feedback is very welcome.

Full transparency: we’re exploring this idea as a potential startup, but we’re still early and figuring out what’s actually useful to developers.

Documentation PR

• I've 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 in new/modified examples
• 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 / plotly.io as pio
• Data frames are always called df
• fig = <something> call is 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=...) in every new/modified example
• Specific adders and updaters like fig.add_shape and fig.update_xaxes are used instead of big fig.update_layout calls in every new/modified example
• fig.show() is at the end of each new/modified example
• plotly.plot() and plotly.iplot() are not used in any new/modified example
• Hex codes for colors are not used in any new/modified example in favour of these nice ones