Miscellaneous updates (#4228)

### What problem does this PR solve?


### Type of change


- [x] Documentation Update

docs/references/http_api_reference.md

@@ -883,6 +883,10 @@ Failure:
 
 ---
 
+## CHUNK MANAGEMENT WITHIN DATASET
+
+---
+
 ### Add chunk
 
 **POST** `/api/v1/datasets/{dataset_id}/documents/{document_id}/chunks`
@@ -936,9 +940,7 @@ Success:
             "content": "ragflow content",
             "create_time": "2024-10-16 08:05:04",
             "create_timestamp": 1729065904.581025,
-            "dataset_id": [
-                "c7ee74067a2c11efb21c0242ac120006"
-            ],
+            "dataset_id": "c7ee74067a2c11efb21c0242ac120006",
             "document_id": "5c5999ec7be811ef9cab0242ac120005",
             "id": "d78435d142bd5cf6704da62c778795c5",
             "important_keywords": []