Merge #1210

1210: Fix getDocument code sample for documenation r=bidoubiwa a=mmachatschek

# Pull Request

## What does this PR do?
Fixes the code sample for `getDocument` on indexes

## PR checklist
Please check if your PR fulfills the following requirements:
- [ ] Does this PR fix an existing issue?
- [x] Have you read the contributing guidelines?
- [x] Have you made sure that the title is accurate and descriptive of the changes?


Co-authored-by: Markus Machatschek <mmachatschek@users.noreply.github.com>

.code-samples.meilisearch.yaml

@@ -14,7 +14,7 @@ update_an_index_1: |-
 delete_an_index_1: |-
   client.deleteIndex('movies')
 get_one_document_1: |-
-  client.getDocument(25684)
+  client.index('movies').getDocument(25684)
 get_documents_1: |-
   client.index('movies').getDocuments({ limit: 2 })
 add_or_replace_documents_1: |-