fixing types and docstrings

haystack/components/retrievers/sentence_window_retriever.py

@@ -143,7 +143,7 @@ def from_dict(cls, data: Dict[str, Any]) -> "SentenceWindowRetriever":
         # deserialize the component
         return default_from_dict(cls, data)
 
-    @component.output_types(context_windows=List[str], context_documents=List[List[Document]])
+    @component.output_types(context_windows=List[str], context_documents=List[Document])
     def run(self, retrieved_documents: List[Document], window_size: Optional[int] = None):
         """
         Based on the `source_id` and on the `doc.meta['split_id']` get surrounding documents from the document store.
@@ -158,9 +158,9 @@ def run(self, retrieved_documents: List[Document], window_size: Optional[int] =
             A dictionary with the following keys:
                 - `context_windows`: A list of strings, where each string represents the concatenated text from the
                                      context window of the corresponding document in `retrieved_documents`.
-                - `context_documents`: A list of lists of `Document` objects, where each inner list contains the
-                                     documents that come from the context window for the corresponding document in
-                                     `retrieved_documents`.
+                - `context_documents`: A list `Document` objects, containing the retrieved documents plus the context
+                                      document surrounding them. The documents are sorted by the `split_idx_start`
+                                      meta field.
 
         """
         window_size = window_size or self.window_size