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

[juanmaguitar]

A section about Block Bindings is missing in the Block Editor Handbook although there's info explaining the possibilities of this feature distributed across different resources:

• New Feature: The Block Bindings API - DevNote
• Introducing Block Bindings, part 1: connecting custom fields - Developer Blog post
• Introducing Block Bindings, part 2: Working with custom binding sources - Developer Blog post
• Editing custom fields from connected blocks - Make WordPress Core post (6.6 updates)

A new section titled Block Bindings with the most relevant info from the resources above could be created under Reference Guides > Block API Reference

cc: @justintadlock @SantosGuillamot

[gziolo]

WordPress 6.7 will ship the client-side counterpart of the API so the related dev note is still pending:

• Block Bindings: Open the stable editor APIs #65713