Merge #1064

1064: Add federated search code-sample r=sanders41 a=ellnix

There is a code sample at https://www.meilisearch.com/docs/reference/api/multi_search#federated-multi-search which most integrations don't seem to have.

Noticed this today and reported on integration-guides: meilisearch/integration-guides#313

Co-authored-by: ellnix <[email protected]>

Author: meili-bors[bot]

.code-samples.meilisearch.yaml

@@ -742,3 +742,8 @@ update_localized_attribute_settings_1: |-
   ])
 reset_localized_attribute_settings_1: |-
   client.index('INDEX_NAME').reset_localized_attributes()
+multi_search_federated_1: |-
+  client.multi_search(
+    [{"indexUid": "movies", "q": "batman"}, {"indexUid": "comics", "q": "batman"}],
+    {}
+  )