Update .code-samples.meilisearch.yaml

Author: meili-bot

.code-samples.meilisearch.yaml

@@ -439,7 +439,10 @@ getting_started_add_documents_md: |-
 
   **Use**
   ```js
-  const client = new MeiliSearch({ host: 'http://localhost:7700' })
+  const client = new MeiliSearch({
+    host: 'http://localhost:7700',
+    apiKey: 'aSampleMasterKey'
+  })
   client.index('movies').addDocuments(movies)
     .then((res) => console.log(res))
   ```