improve first contact with jupyter lite build

[parmentelat]

Problem

I was giving a try at building my first jupyter lite, and ran across a few imperfections, so I thought I'd try to list them as an fyi

• the documentation focuses on deploying through github actions; which is clearly something that one will ultimately do, but imho for a first attempt it would be more rewarding to first run a jupyter lite build command locally; also because it shortens the workflow, to be able to look at the result locally before pushing to github; so imho again the doc could be split in 2, first a quick local build, then go for the github actions approach
• while running my first jupyter lite build locally:
  • symlinks inside the contents area but pointing outside of it are raising an exception like so; just ignore them, or issue a warning instead ?
    console ValueError: 'blabla/tools/rename-all-notebooks-as-nb.sh' is not in the subpath of 'blabla/notebooks' OR one path is relative and the other is absolute.
  • likewise the contents folder had a .vscode folder that was causing problems; the error message was clear enough, I needed to remove that folder (or reconfigure, but that looked tedious as I did not really needed the .vscode thingy); however that hidden folder was still in the destination folder, which I had to manually remove before starting over again
• once the site was built, when opening it
  • I had to go through a local webserver using python -m http.server because of CORS restrictions when fetching config-util.js
  • at which point I was getting a ReferenceError: Babel is not defined
  • in addition to config-util.js still not being loaded, this time with a Failed to fetch dynamically imported module: http://localhost:8000/config-utils.js

this is as far as I'm being able to go

Proposed Solution

I guess I can see 2 options

• either this is known to be overcomplex, in which case the doc should clearly state that
• or there could be a first chapter in https://jupyterlite.readthedocs.io/en/latest/quickstart/deploy.html that gives an overview on how to do this; this is particularly relevant for people who would want to try it out quickly with preexisting content

Additional context

this is just some raw reporting bout my first experience, please ignore if not useful

[parmentelat]

PS.
As a second attempt, and to avoid any mistake on my end, I have used a local replica of
https://github.com/widgetti/ipyreact
since this repo is successfully exposed through githubactions as
https://widgetti.github.io/ipyreact/lab/index.html

but I'm primarily experiencing the same errors as above, specifically

• the ReferenceError: Babel is not defined
• and this other one Failed to fetch dynamically imported module: http://localhost:8000/config-utils.js

[oscar6echo]

so imho again the doc could be split in 2, first a quick local build, then go for the github actions approach

This PR tries to tackle this point - now where to put it / how to present it is an open question.
jupyterlite/demo#117