Initial Commit of Clean Slate

[onuro]

This PR introduces the Clean Slate theme, a blank/starter theme in replacement of Blank Canvas, started out with the purpose of using in Pattern Assembler project.

This theme is a stripped down version of TT3 theme, with some more custom theme.json and template parts updates.

I've kept the fonts from TT3, as the use of a fonts library for this theme TBD.

Please let me know what could be improved with this theme, as I'm still checking for things that may be needed to be updated.

Thank you!

[scruffian]

I think if we want a truly clean slate we should remove a lot more - all the patterns for example can go, and quite a few of the templates as well.

[scruffian]

What happens if we remove all templates except index?

[onuro]

What happens if we remove all templates except index?

Tbh makes sense. @mtias this is also something along the lines of what you've expressed for this right?

[alaczek]

I'm also wondering about the inclusion of font assets. What do you think about removing them and reverting to using system fonts?

[arthur791004]

Could we have the home.html file without any content and use it to display the home page of this theme? cc @mtias

[scruffian]

I'm not clear how "blank" we want this to be. The templates still contain a lot of opinion. Do we want to strip it back to just display page content?