Docs: Create a section about Block Bindings in the Block Editor Handbook

[gziolo]

A section about Block Bindings could be added to the Block API Reference to help discover Block Hooks docs.

Current info about Block Bindings in the Block Editor Handbook is available only as dev notes or blog posts which covers the server part:

• Dev note: The Block Bindings API.
• Introducing Block Bindings, part 1: connecting custom fields.
• Introducing Block Bindings, part 2: Working with custom binding sources.

WordPress 6.7 will ship the client-side counterpart of the API:

• Block Bindings: Open the stable editor APIs #65713

[gziolo]

There was an existing issue #63026 😅