feat: Add management command to load demo content

[mrbazzan]

This pull request address issue #73 .
It adds a management command to load data exported using djangocms-transfer.

It works by running docker compose --rm web python manage.py democontent demo-content/help.json.
I would like to remove the FILE positional argument from the command so it becomes
docker compose --rm web python manage.py democontent but we would need to finalise the content that
would be in the remote URI (which we would then use internally).

[fsbraun]

Hi @mrbazzan ! I will give it a test run in the coming days. A few thoughts:

• Is it possible to rename the folder to "democontent" to be consistent with the command?
• Can the command list the options (i.e. files in the democontent folder) if you do not specify any?
• If only a file name and no path is specified, can the command automatically read from the democontent folder?
• Another option would be to call the new page "help-2" if "help" already existed.

[mrbazzan]

• Another option would be to call the new page "help-2" if "help" already existed.

Hi @fsbraun, won't that cluster the page tree?
If there is help-2, we create help-3 and it continues like that.
Shouldn't the user be explicit about the page they want created?

[fsbraun]

• Another option would be to call the new page "help-2" if "help" already existed.

Hi @fsbraun, won't that cluster the page tree? If there is help-2, we create help-3 and it continues like that. Shouldn't the user be explicit about the page they want created?

Alternatively, to avoid unintended clustering, you can add a --force option which would import (using the names as you suggested). So, without --force it would fail, and with --force you can add any page many times.

[mrbazzan]

Alternatively, to avoid unintended clustering, you can add a --force option which would import (using the names as you suggested). So, without --force it would fail, and with --force you can add any page many times.

I have added the --force option. django-cms creates the same title with different slug.

[fsbraun]

LGTM!