Add devcontainer config with GitHub Copilot extensions (#3815)

Author: deyaaeldeen

.devcontainer/devcontainer.json

@@ -0,0 +1,10 @@
+{
+  "customizations": {
+    "vscode": {
+      "extensions": [
+        "GitHub.copilot",
+        "GitHub.copilot-chat"
+      ]
+    }
+  }
+}