fix: extract extensions of child items in case it is a single object

Author: Christian

src/services/models/Schema.ts

@@ -96,6 +96,13 @@ export class SchemaModel {
 
     if (options.showExtensions) {
       this.extensions = extractExtensions(this.schema, options.showExtensions);
+
+      if (typeof this.schema.items === 'object') {
+        this.extensions = {
+          ...this.extensions,
+          ...extractExtensions(this.schema.items, options.showExtensions),
+        };
+      }
     }
   }