This bash file when executed scaffolds a theme structure with just the bare essentials of a BBT (Block Based Theme).

create-bare-bbt.bash

#! /bin/bash


mkdir "$PWD"/bare-bbt

touch "$PWD"/bare-bbt/style.css

mkdir "$PWD"/bare-bbt/templates "$PWD"/bare-bbt/parts

cat << DELIMITER >> "$PWD"/bare-bbt/parts/header.html
<!-- wp:site-title /--> 
DELIMITER

touch "$PWD"/bare-bbt/parts/header.html

cat << DELIMITER >> "$PWD"/bare-bbt/templates/index.html
<!-- wp:template-part {"slug":"header"} /-->
<!-- wp:query -->
<div class="wp-block-query">
<!-- wp:post-template -->
<!-- wp:post-title /-->
<!-- wp:post-date /-->
<!-- wp:post-content /-->
<!-- /wp:post-template -->
</div>
<!-- /wp:query -->
DELIMITER