Add docs for the AAS Registry Bulk API

basyx.aasregistry/basyx.aasregistry-service/README.md

@@ -5,3 +5,21 @@ The base server implementation was generated by the [openAPI generator](https://
 It is based on [Spring Boot](https://spring.io/projects/spring-boot) and logs shell or submodel registration-updates. The storage implementation is missing. You can either use the inMemory implementation or mongoDb implementation provided by sibling projects or implement your storage.
 
 Use the basyx.aasregistry-basemodel project if you want to use just POJOs generated out of the OpenAPI description. You can also generate or implement other model classes with specific annotations as we do it for the mongodb-storage implementation.
+
+## AAS Registry Bulk API
+
+The AAS Registry Bulk API facilitates efficient management of Asset Administration Shell (AAS) Descriptors through bulk operations. It is designed for high-volume handling, enabling batch creation, update, and deletion of AAS Descriptors, alongside querying operation statuses and results.
+
+_Note:_ This API is currently only available for the MongoDB backend. It's enabled automatically for this configuration.
+
+### Endpoints
+
+- **POST /bulk/shell-descriptors**: Batch creation of AAS Descriptors.
+- **PUT /bulk/shell-descriptors**: Bulk update of existing AAS Descriptors.
+- **DELETE /bulk/shell-descriptors**: Batch deletion of AAS Descriptors by their identifiers.
+- **GET /bulk/status/{handleId}**: Retrieve the status of a bulk operation.
+- **GET /bulk/result/{handleId}**: Obtain the result of a completed bulk operation.
+
+### Usage
+
+To use the bulk operations, clients should structure their requests to include a list of AAS Descriptors (for creation or update) or identifiers (for deletion) in the request body, adhering to the specified content type and structure. The status and result of these operations can be monitored and retrieved using the `handleId` provided by the initial operation response.