Docs: Update link for Inner Blocks

[mkaz]

Description

The Inner Blocks component is linked to the wrong spot, the old link is going to /packages/editor/src/components/inner-block/README.md the new location should be block-editor package.

This PR updates the link on block-registration, and block-templtes page.

However, I don't think the actually Inner Block documentation is being published anywhere.

@nosolosw if I look in the source repo on Github, the readme file is there for Inner Blocks.
See: https://github.com/WordPress/gutenberg/tree/master/packages/block-editor/src/components/inner-blocks

However, if I look at the Gutenberg Handbook, it looks empty here
https://wordpress.org/gutenberg/handbook/designers-developers/developers/packages/packages-block-editor/#InnerBlocks

Types of changes

Documentation

[jorgefilipecosta]

LGTM 👍

[oandregal]

mmm, it looks like we have a bunch of links pointing to the wrong URLs. We should either:

1. Use full URLs for files that aren't published to the handbook (all component's READMEs, things that live within */src/*, etc.): https://wordpress.org/gutenberg/handbook/designers-developers/developers/packages/packages-block-editor/#InnerBlocks

2. Use relative URLs to the handbook docs: /docs/designers-developers/developers/packages/packages-block-editor/#InnerBlocks

[oandregal]

However, I don't think the actually Inner Block documentation is being published anywhere.

Yup, it's not. To my knowledge, it was never published to the handbook. Note that https://wordpress.org/gutenberg/handbook/designers-developers/developers/packages/packages-block-editor/#InnerBlocks uses the info from the JSDoc comments (in this case there is none).

Here are some thoughts on how we could improve this:

• most components aren't documented (as in: they have JSDoc comments).
• many components do have a README file.

What if we moved the relevant info from the component's README to JSDoc comments, then automatically fill both the component's README and the handbook page? This is one of the tasks I'm tracking on #14227 At the moment the ./bin/update-readmes only updates the packages' README, but we could adapt it to also update the inner component's READMEs.

[mkaz]

Ok, I'll merge this one which "fixes" the link at least to the right packages section.

We can track the sub-components on your at #14227 - I need to dig in a little more to understand completely. My initial hunch is that it is probably best to try and match the handbook docs to Github directory structure as much as possible.

The /packages/ relative URL does get transform to work when viewing the handbook, but not sure if the links work properly in the npm and github contexts of viewing documentation. A quick search and it looks like 20 or so spots are linking this way.