`update_embedders_1` sample does not use the `embedders` route

[ellnix]

In update embedders settings, the endpoint is PATCH /indexes/{index_uid}/settings/embedders. However, the curl code sample uses the main /settings endpoint:

curl \
  -X PATCH 'http://localhost:7700/indexes/INDEX_NAME/settings' \
  -H 'Content-Type: application/json' \
  --data-binary '{
    "embedders": {
      "default": {
        "source":  "openAi",
        "apiKey": "anOpenAiApiKey",
        "model": "text-embedding-3-small",
        "documentTemplate": "A document titled '{{doc.title}}' whose description starts with {{doc.overview|truncatewords: 20}}"
      }
    }
  }'