Proposal: Auto-generate Block Editor Handbook docs from block.json

A proposal to auto-generate Block Editor Handbook documentation from each core block's block.json file. The pipeline would create per-block API reference pages at build time, keeping docs in sync with the codebase automatically. Generated content lives in README.md files next to block source code, using token delimiters to preserve hand-written narrative alongside auto-generated API reference. The initial PR was merged then reverted due to insufficient community discussion, and this post opens a formal feedback period running through May 25th with a Hallway Hangout on May 18th.