The reuse README should contain an overview of the features provided by the GraphQL service. It currently only has the description for the "labels of linked entities" feature, but not for the other two.
Acceptance criteria:
- The README has a description including an example for the "getting data of multiple items" feature (itemsById field)
- The README has a description including an example for the "searching items by statement property and value" feature (searchItems field)