doc: fixing colab (#78)

* doc: fixing colab

---------

Co-authored-by: Hailong Li <[email protected]>
Co-authored-by: Kurtis Van Gent <[email protected]>

Author: 3 people

samples/langchain_quick_start.ipynb

@@ -498,6 +498,15 @@
                 "\n",
                 "sample_vector_table_name = \"movie_vector_table_samples\"\n",
                 "\n",
+                "pg_engine = PostgresEngine.from_instance(\n",
+                "    project_id=project_id,\n",
+                "    instance=instance_name,\n",
+                "    region=region,\n",
+                "    database=database_name,\n",
+                "    user=\"postgres\",\n",
+                "    password=password,\n",
+                ")\n",
+                "\n",
                 "pg_engine.init_vectorstore_table(\n",
                 "    sample_vector_table_name,\n",
                 "    vector_size=768,\n",
@@ -742,12 +751,12 @@
                 "    PostgresChatMessageHistory,\n",
                 ")\n",
                 "\n",
-                "# Intialize the embedding service\n",
+                "# Initialize the embedding service\n",
                 "embeddings_service = VertexAIEmbeddings(\n",
                 "    model_name=\"textembedding-gecko@latest\", project=project_id\n",
                 ")\n",
                 "\n",
-                "# Intialize the engine\n",
+                "# Initialize the engine\n",
                 "pg_engine = PostgresEngine.from_instance(\n",
                 "    project_id=project_id,\n",
                 "    instance=instance_name,\n",
@@ -757,7 +766,7 @@
                 "    password=password,\n",
                 ")\n",
                 "\n",
-                "# Intialize the Vector Store\n",
+                "# Initialize the Vector Store\n",
                 "vector_table_name = \"movie_vector_table\"\n",
                 "vector_store = PostgresVectorStore.create_sync(\n",
                 "    engine=pg_engine,\n",
@@ -774,7 +783,7 @@
                 "    ],\n",
                 ")\n",
                 "\n",
-                "# Intialize the PostgresChatMessageHistory\n",
+                "# Initialize the PostgresChatMessageHistory\n",
                 "chat_history = PostgresChatMessageHistory.create_sync(\n",
                 "    pg_engine,\n",
                 "    session_id=\"my-test-session\",\n",
@@ -844,7 +853,7 @@
             },
             "outputs": [],
             "source": [
-                "# Intialize retriever, llm and memory for the chain\n",
+                "# Initialize retriever, llm and memory for the chain\n",
                 "retriever = vector_store.as_retriever(\n",
                 "    search_type=\"mmr\", search_kwargs={\"k\": 5, \"lambda_mult\": 0.8}\n",
                 ")"
@@ -856,7 +865,7 @@
                 "id": "3maZ8SLlneYJ"
             },
             "source": [
-                "Now let's intialize our LLM, in this case we are using Vertex AI's \"gemini-pro\"."
+                "Now let's initialize our LLM, in this case we are using Vertex AI's \"gemini-pro\"."
             ]
         },
         {