将npm install 放到postAttachCommand阶段

.devcontainer/devcontainer.json

@@ -18,6 +18,5 @@
             "onAutoForward": "notify"
         }
     },
-  "postCreateCommand": "npm install &&  npm add -D vitepress",
-  "postAttachCommand": "npm run docs:dev -- --host 0.0.0.0"
+  "postAttachCommand": "npm install &&  npm add -D vitepress npm run docs:dev -- --host 0.0.0.0"
 }