Add theme.json file and remove few theme support from php file

[devanshijoshi9]

Description

• Add theme.json file.

Checklist

• [x] Add theme.json file.
• [x] Remove some theme_supports from php file.

Fixes/Covers issue

Fixes #80

Note- Keep few of the theme support in php as I am unable to find theme support in theme.json file. Here is the reference.

[RahiDroid]

Just a note, I believe hybrid themes require the CSS on FE to be added manually using the tokens generated by the theme.json file.

Please verify it once before letting it through.

[RahiDroid]

Just a note, I believe hybrid themes require the CSS on FE to be added manually using the tokens generated by the theme.json file.

Please verify it once before letting it through.

@robicse11127 Please verify this, update the theme.json if there are any changes required, and test out the other changes in this PR.

[robicse11127]

theme.json Looks okay to me

[RahiDroid]

@robicse11127

Just a note, I believe hybrid themes require the CSS on FE to be added manually using the tokens generated by the theme.json file.

Please verify it once before letting it through.

Verified this or you're yet to do it?

[robicse11127]

@RahiDroid Adding styling in theme.json is applied in both editor and FE. So if any style added in the theme.json should also be impacted in the FE.

[RahiDroid]

@robicse11127 The theme.json file misses out on demonstrating many things that are possible with it. For example, Color palettes, Typography related presets, Spacing presets, Default styling for blocks, Custom variables, etc.

Could you please include some examples demonstrating those in the theme.json file? The Blank theme is supposed to be design-neutral, so please include some basic palette and other presets for demonstration purpose only.

If you want, you can refer Twenty-TwentyThree theme's theme.json file.

[robicse11127]

@RahiDroid Got it. I have updated the theme.json with some example presets.