Fix bug with missing items entry (#36)

Co-authored-by: Maria Haberland <82449221+mh-at-fujitsu@users.noreply.github.com>

Author: mh7d

openapidocs/mk/v3/examples.py

@@ -117,7 +117,7 @@ def get_example(self, schema) -> Any:
             $ref: '#/components/schemas/ReleaseNodeDownload'
           nullable: true
         """
-        items = schema["items"]
+        items = schema.get("items", [])
 
         if not isinstance(items, list):
             items = [items]