[FR] support alternate checkboxes

[KraXen72]

Is your feature request related to a problem? Please describe.
alternate checkbox styles are not supported
see:

Describe the solution you'd like

see https://minimal.guide/Block+types/Checklists#Checkbox+icons for which ones to implement

Describe alternatives you've considered
adding this as an optional style setting since not everyone might want it

Additional context

Checklist

• I have checked that the feature is not already available via the Style Settings plugin.

[tingmelvin]

I think alternate checkboxes are quite finicky and people tend to have their differing classifications, so I won't implement it.

I understand that you might have gotten the code from kepano, once the rewrite is done I'll drop the same Minimal snippet into the theme docs (at willemstad.cc) for others to use 👍

[KraXen72]

sure. i posted in showcase notes a python script that grabs and patches kepanos checkboxes as a snippet, feel free to reference it