Slim, single-responsibility WordPress plugin that adds a table of contents block to the WordPress 5 block editor.
Based on the sortabrilliant block Guidepost, but with support for infinite nesting of blocks (the original block only scans the top level post content). This block is also devoid of any and all frontend JS while the original uses some jQuery spitshine.
Anyway, hattip sortabrilliant, it's a bomb idea.
