Add genres field to IncompleteMovie struct

Add the missing genre field to the code samples

Author: pacifistes

.code-samples.meilisearch.yaml

@@ -168,15 +168,17 @@ add_or_update_documents_1: |-
   #[derive(Serialize, Deserialize)]
   struct IncompleteMovie {
     id: usize,
-    title: String
+    title: String,
+    genres: String
   }
 
   let task: TaskInfo = client
     .index("movies")
     .add_or_update(&[
       IncompleteMovie {
         id: 287947,
-        title: "Shazam ⚡️".to_string()
+        title: "Shazam ⚡️".to_string(),
+        genres: "comedy".to_string()
       }
     ], None)
     .await