docs - embed quick start (#37059)

docs/README.md

docs/embedding/images/all-users.png

docs/embedding/images/jwt-setup.png

docs/embedding/images/map-user-attribute.png

docs/embedding/images/sandboxed-invoices-table.png

docs/embedding/images/sync-groups.png

docs/embedding/interactive-embedding-quick-start-guide.md

docs/embedding/interactive-embedding.md

docs/embedding/start.md