BREAKING: repository structure change

.devcontainer/devcontainer.json

@@ -0,0 +1,24 @@
+{
+  "image": "ghcr.io/rocker-org/devcontainer/r-ver:4",
+  "features": {
+    "ghcr.io/devcontainers/features/docker-in-docker:2": {
+      "dockerDashComposeVersion": "v2"
+    },
+    "ghcr.io/rocker-org/devcontainer-features/r-history:0": {}
+  },
+  "customizations": {
+    "vscode": {
+      "extensions": [
+        "DavidAnson.vscode-markdownlint",
+        "EditorConfig.EditorConfig",
+        "esbenp.prettier-vscode",
+        "foxundermoon.shell-format"
+      ],
+      "settings": {
+        "[r]": {
+          "editor.tabSize": 2
+        }
+      }
+    }
+  }
+}