Implemented the GET / endpoint for the Open API specification documentation in the library target.

Sources/DiscogsService/openapi.yaml

@@ -247,9 +247,9 @@ paths:
     get:
       tags:
         - Service
-      operationId: service
       summary: Get service information.
       description:  Retrieves any available information related to the service.
+      operationId: getService
       responses: 
         '200':
           description: Service information returned successfully.
@@ -261,56 +261,57 @@ paths:
           $ref: '#/components/responses/Unavailable'
 components:
   schemas:
-    Error:
+    Service:
+      description: A type that encapsulates any available information about the service.
+      type: object
+      properties:
+        api_version:
+          description: A current API version of the service.
+          type: string
+        documentation_url:
+          description: A URI link to the Developers' documentation available online.
+          type: string
+          format: uri
+        hello:
+          description: A welcome message send by the service.
+          type: string
+        statistics:
+          description: A type that encapsulates statistical data about the service.
+          type: object
+          properties:
+            artists:
+              description: A total number of artists registered in the service.
+              type: integer
+            labels:
+              description: A total number of labels registered in the service.
+              type: integer
+            releases:
+              description: A total number of releases registered in the service.
+              type: integer
+          required:
+            - artists
+            - labels
+            - releases
+      required:
+        - api_version
+        - documentation_url
+        - hello
+        - statistics
+    ServiceError:
+      description: A type that contains any error data.
       type: object
       properties:
         message:
+          description: A message of a service error.
           type: string
-    Service:
-      type: object
-      description: A type that contains all available service information.
-      properties:
-        hello:
-          description: A welcome message from the service.
-          type: string
-        api_version:
-          description: A current version of the service.
-          type: string
-        documentation_url:
-          description: A URL to the developers' documentation.
-          type: string
-        statistics:
-          type: object
-          description: A type that contains the service's statistics.
-          properties:
-            releases:
-              description: A number of registered releases in the service.
-              type: integer
-            artists:
-              description: A number of registered artists in the service.
-              type: integer
-            labels:
-              description: A number of registered labels in the service.
-              type: integer
+      required: 
+        - message
   responses:
     Unavailable:
       description: The service is currently unavailable to handle requests.
       content:
         application/json:
           schema:
-            $ref: '#/components/schemas/Error'
-          examples:
-            timeout:
-              value:
-                message: Query time exceeded. Please try a simpler query.
-            malformed:
-              value: 
-                message: An internal server error occurred.
-    Unauthorized:
-      description: Some authentication information is missing or invalid.
-      content:
-        application/json:
-          schema:
-            $ref: '#/components/schemas/Error'
+            $ref: '#/components/schemas/ServiceError'
           example:
-            message: Service not available.
+            message: Server is currently unavailable.