chore: add opening sentence to __init__ docstrings in unstructured and valkey

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: julian-risch

integrations/unstructured/src/haystack_integrations/components/converters/unstructured/converter.py

@@ -56,6 +56,8 @@ def __init__(
         progress_bar: bool = True,  # noqa: FBT001, FBT002
     ) -> None:
         """
+        Create an `UnstructuredFileConverter` instance.
+
         :param api_url: URL of the Unstructured API. Defaults to the URL of the hosted version.
             If you run the API locally, specify the URL of your local API (e.g. `"http://localhost:8000/general/v0/general"`).
         :param api_key: API key for the Unstructured API.

integrations/valkey/src/haystack_integrations/components/retrievers/valkey/embedding_retriever.py

@@ -68,6 +68,8 @@ def __init__(
         filter_policy: str | FilterPolicy = FilterPolicy.REPLACE,
     ) -> None:
         """
+        Create a `ValkeyEmbeddingRetriever` instance.
+
         :param document_store: The Valkey Document Store.
         :param filters: Filters applied to the retrieved Documents.
         :param top_k: Maximum number of Documents to return.