Use feature-based devcontainer and add dependabot

.devcontainer/devcontainer.json

@@ -3,10 +3,15 @@
 {
     "name": "F# (.NET)",
     // Or use a Dockerfile or Docker Compose file. More info: https://containers.dev/guide/dockerfile
-    "image": "mcr.microsoft.com/devcontainers/dotnet:1-6.0-bookworm",
+    "image": "mcr.microsoft.com/devcontainers/base:debian",
 
     // Features to add to the dev container. More info: https://containers.dev/features.
-    // "features": {},
+    "features": {
+        "ghcr.io/devcontainers/features/dotnet:2": {
+            "version": "8.0",
+            "additionalVersions": "6.0"
+        }
+    },
 
     // Configure tool-specific properties.
     "customizations": {
@@ -20,10 +25,7 @@
                 "gruntfuggly.todo-tree",
                 "ms-dotnettools.csharp",
                 "Ionide.Ionide-fsharp"
-            ],
-            "settings": {
-                "FSharp.dotnetRoot": "/usr/bin"
-            }
+            ]
         }
     },
 

.github/dependabot.yml

@@ -0,0 +1,24 @@
+# To get started with Dependabot version updates, you'll need to specify which
+# package ecosystems to update and where the package manifests are located.
+# Please see the documentation for more information:
+# https://docs.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
+# https://containers.dev/guide/dependabot
+
+version: 2
+updates:
+  - package-ecosystem: "devcontainers"
+    directory: "/"
+    groups:
+      features:
+        patterns:
+          - "*"
+    schedule:
+      interval: monthly
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    groups:
+      actions:
+        patterns:
+          - "*"
+    schedule:
+      interval: monthly