docs: Add Comments and Supplementary Example Code to Vearch Vector Dat… (#29706)

- **Description:** Added some comments to the example code in the Vearch
vector database documentation and included commonly used sample code.
- **Issue:** None
- **Dependencies:** None

---------

Co-authored-by: wangchuxiong <wangchuxiong@jd.com>

docs/docs/integrations/vectorstores/vearch.ipynb

@@ -156,6 +156,15 @@
     "    db_name=\"vearch_cluster_langchian\",\n",
     "    table_name=\"tobenumone\",\n",
     "    flag=1,\n",
+    ")\n",
+    "\n",
+    "# The vector data is usually already initialized, so we don’t need the document parameter and can directly create the object.\n",
+    "vearch_cluster_b = Vearch(\n",
+    "    embeddings,\n",
+    "    path_or_url=\"http://test-vearch-langchain-router.vectorbase.svc.ht1.n.jd.local\",\n",
+    "    db_name=\"vearch_cluster_langchian\",\n",
+    "    table_name=\"tobenumone\",\n",
+    "    flag=1,\n",
     ")"
    ]
   },
@@ -244,6 +253,7 @@
    ],
    "source": [
     "query = \"你知道凌波微步吗，你知道都有谁会凌波微步?\"\n",
+    "# The second parameter is the top-n to retrieve, and its default value is 4.\n",
     "vearch_standalone_res = vearch_standalone.similarity_search(query, 3)\n",
     "for idx, tmp in enumerate(vearch_standalone_res):\n",
     "    print(f\"{'#'*20}第{idx+1}段相关文档{'#'*20}\\n\\n{tmp.page_content}\\n\")\n",
@@ -261,6 +271,11 @@
     "for idx, tmp in enumerate(cluster_res):\n",
     "    print(f\"{'#'*20}第{idx+1}段相关文档{'#'*20}\\n\\n{tmp.page_content}\\n\")\n",
     "\n",
+    "# In practical applications, we usually limit the boundary value of similarity. The following method can set this value.\n",
+    "cluster_res_with_bound = vearch_cluster.similarity_search_with_score(\n",
+    "    query=query_c, k=3, min_score=0.5\n",
+    ")\n",
+    "\n",
     "# combine your local knowleadge and query\n",
     "context_c = \"\".join([tmp.page_content for tmp in cluster_res])\n",
     "new_query_c = f\"基于以下信息，尽可能准确的来回答用户的问题。背景信息:\\n {context_c} \\n 回答用户这个问题:{query_c}\\n\\n\"\n",