Numerous sub-components have readme and documentation created, but these are not surfaced in the Gutenberg Handbook, and thus can not easily be linked to.

One example is InnerBlocks, the component documentation is here:
https://github.com/WordPress/gutenberg/tree/master/packages/block-editor/src/components/inner-blocks

But the Gutenberg Handbook documentation for Block Editor shows as it is undocumented here: https://wordpress.org/gutenberg/handbook/designers-developers/developers/packages/packages-block-editor/

Which also means we can't link to it from places like here, which tries but is a broken link
https://wordpress.org/gutenberg/handbook/designers-developers/developers/block-api/block-templates/