[36842] Add pre-commit script to generate ER mermaid diagram from SQL…

[dennysreg]

Closes: #36842

Use paracelsus to generate the docs/apache-airflow/img/airflow_erd.svg file based on SQLAlchemy models.

NOTE: The same tool could be use to generate a mermaid code and inject it to a Markdown file but it seems like rst format is not supported yet.

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[boring-cyborg]

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[uranusjr]

Is it necessary to put this in README? I’m not sure that’s particularly useful TBH…

[dennysreg]

Not really, we should find a better place to embed it. It was just the first markdown file I found. Any suggestions?

[uranusjr]

The user-facing documentation already has an image, so maybe somewhere in contributing-docs? IIRC there’s a document there on database models.

[dennysreg]

Unfortunately I can't inject the mermaid in the rst file so I just replace the svg file instead
and restore the original README
https://github.com/dennysreg/airflow/blob/issue-36842-generate-a-mermaid-erd-diagram-from-sqlalchemy-models/docs/apache-airflow/database-erd-ref.rst

[potiuk]

@dennysreg - do you think you can rebase it and make it ready to be merged?