Issue #2961431 by ressa: Migrate from local JSON file?

migrate_json_example/README.md

migrate_json_example/artifacts/products.json

...ptional/core.entity_form_display.node.product.default.yml

...ptional/core.entity_view_display.node.product.default.yml

...g/optional/field.field.node.product.field_description.yml

.../config/optional/field.field.node.product.field_price.yml

...le/config/optional/field.field.node.product.field_upc.yml

.../config/optional/field.storage.node.field_description.yml

...xample/config/optional/field.storage.node.field_price.yml

..._example/config/optional/field.storage.node.field_upc.yml

...xample/config/optional/migrate_plus.migration.product.yml

migrate_json_example/config/optional/node.type.product.yml

migrate_json_example/migrate_json_example.info.yml

migrate_json_example/migrate_json_example.install