Update devcontainer.json for changes to devcontainer schema

Author: ryboe

.devcontainer/devcontainer.json

@@ -3,18 +3,22 @@
     "build": {
         "dockerfile": "Dockerfile"
     },
-    "settings": {
-        "[dockerfile]": {
-            "editor.defaultFormatter": "ms-azuretools.vscode-docker"
-        },
-        "editor.formatOnSave": true,
-        "files.insertFinalNewline": true,
-        "files.trimFinalNewlines": true,
-        "files.trimTrailingWhitespace": true
-    },
-    "extensions": [
-        "davidanson.vscode-markdownlint",
-        "ms-azuretools.vscode-docker",
-        "redhat.vscode-yaml"
-    ]
+    "customizations": {
+        "vscode": {
+            "settings": {
+                "[dockerfile]": {
+                    "editor.defaultFormatter": "ms-azuretools.vscode-docker"
+                },
+                "editor.formatOnSave": true,
+                "files.insertFinalNewline": true,
+                "files.trimFinalNewlines": true,
+                "files.trimTrailingWhitespace": true
+            },
+            "extensions": [
+                "davidanson.vscode-markdownlint",
+                "ms-azuretools.vscode-docker",
+                "redhat.vscode-yaml"
+            ]
+        }
+    }
 }