feature request: Allow launching the Solara server via python app.py

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Currently, there are 2 ways to run the Solara app:

• solara run app.py
• Launch a Jupyter notebook server, then execute the cells in app.py

My request is to have an option to do python app.py so that it is easier to document. Though, saying solara run app.py already works. Perhaps a better use (though this is not my use case at the moment) case would be to have another web server code that launches the Solara server programmatically.

[rht]

Though a subprocess.Popen(["solara", "run", "app.py"]) would have worked too.