yjs 13.4.0-0

on Node.js Yarn

• implemented first subdocuments draft #234 e17d661
• Merge branch 'josephg-main' into main dadc085
• Finishing up INTERNALS.md e769a2a
• Added draft of INTERNALS.js describing how Yjs works 0dd0a4b
• properly annotate DeltaItem.insert - fixes #227 b4fc073
• fix readme formatting 6a9f853

v13.3.2...v13.4.0-0