added customization

.devcontainer/devcontainer.json

@@ -5,5 +5,18 @@
      "image": "mcr.microsoft.com/vscode/devcontainers/universal:latest",
 
      "remoteUser": "codespace",
-     "overrideCommand": false
-   }
+     "overrideCommand": false,
+     // Add the IDs of extensions you want installed when the container is created.
+     "customizations": {
+         "vscode": {
+             "extensions": [
+                 "GitHub.copilot"
+             ]
+         },
+         "codespaces": {
+             "openFiles": [
+                 "codespace.md"
+             ]
+         }
+     }
+   }