Add the installation step of postgresql and pgvector on windows in LlamaIndex GPU support (#10328)

* add the installation of postgresql and pgvector of windows

* fix some format

python/llm/example/GPU/LlamaIndex/README.md

@@ -21,6 +21,7 @@ The RAG example ([rag.py](./rag.py)) is adapted from the [Official llama index R
     Follow the instructions in [GPU Install Guide](https://bigdl.readthedocs.io/en/latest/doc/LLM/Overview/install_gpu.html) to install bigdl-llm.
 
 * **Database Setup (using PostgreSQL)**:
+    * Linux
         * Installation: 
             ```bash
             sudo apt-get install postgresql-client
@@ -28,18 +29,40 @@ The RAG example ([rag.py](./rag.py)) is adapted from the [Official llama index R
             ```
         * Initialization:
             
-      Switch to the **postgres** user and launch **psql** console:
+            Switch to the **postgres** user and launch **psql** console
             ```bash
             sudo su - postgres
             psql
             ```
+            
             Then, create a new user role:
             ```bash
             CREATE ROLE <user> WITH LOGIN PASSWORD '<password>';
             ALTER ROLE <user> SUPERUSER;    
             ```
+    * Windows
+        * click `Download the installer` in [PostgreSQL](https://www.postgresql.org/download/windows/).  
+        * Run the downloaded installation package as administrator, then click `next` continuously.  
+        * Open PowerShell:
+        ```bash
+            cd C:\Program Files\PostgreSQL\14\bin
+        ```   
+        The exact path will vary depending on your PostgreSQL location.  
+        * Then in PowerShell:
+        ```bash
+            .\psql -U postgres    
+        ```   
+        Input the password you set in the previous installation. If PowerShell shows `postgres=#`, it indicates a successful connection.
+        * Create a new user role:
+        ```bash
+        CREATE ROLE <user> WITH LOGIN PASSWORD '<password>';
+        ALTER ROLE <user> SUPERUSER;    
+        ```
 * **Pgvector Installation**:
-    Follow installation instructions on [pgvector's GitHub](https://github.com/pgvector/pgvector) and refer to the [installation notes](https://github.com/pgvector/pgvector#installation-notes) for additional help.
+    * Linux
+        * Follow installation instructions on [pgvector's GitHub](https://github.com/pgvector/pgvector) and refer to the [installation notes](https://github.com/pgvector/pgvector#installation-notes) for additional help.
+    * Windows 
+        * It is recommended to use [pgvector for Windows](https://github.com/pgvector/pgvector?tab=readme-ov-file#windows) instead of others (such as conda-force) to avoid potential errors. Some steps may require running as administrator.
 
 
 * **Data Preparation**: Download the Llama2 paper and save it as `data/llama2.pdf`, which serves as the default source file for retrieval.