update docs/readme.md and design folder (#234)

Signed-off-by: hsliu <liuhongsheng4@huawei.com>

docs/.nav.yml

@@ -32,7 +32,13 @@ nav:
     - design/index.md
     - design/architecture_overview.md
     - design/vllm_omni_design.md
-    - design/mrs_design.md
+    - Feature Design:
+      - design/feature/multi_request_streaming_design.md
+      - design/feature/omni_connector_design.md
+    - Module Design:
+      - design/module/ar_module_design.md
+      - design/module/dit_module_design.md
+      - design/module/entrypoint_module_design.md
   - Docs Guide: contributing/DOCS_GUIDE.md
 - API Reference:
   - api/README.md