docs: enhance README and README_zh-CN with improved backend feature table and community feedback section

README.md

@@ -629,7 +629,7 @@ A WebUI developed based on Gradio, with a simple interface and only core parsing
         <tr>
             <th>transformers</th>
             <th>mlx-engine</th>
-            <th>vllm-engine/vllm-async-engine</th>
+            <th>vllm-engine / <br>vllm-async-engine</th>
             <th>http-client</th>
         </tr>
     </thead>

README_zh-CN.md

@@ -616,7 +616,7 @@ https://github.com/user-attachments/assets/4bea02c9-6d54-4cd6-97ed-dff14340982c
         <tr>
             <th>transformers</th>
             <th>mlx-engine</th>
-            <th>vllm-engine/vllm-async-engine</th>
+            <th>vllm-engine / <br>vllm-async-engine</th>
             <th>http-client</th>
         </tr>
     </thead>