Add docker to the dev container

Author: kevinbackhouse

.devcontainer/devcontainer.json

@@ -15,7 +15,10 @@
     },
     "ghcr.io/devcontainers/features/github-cli:1": {
       "version": "latest"
-    }
+    },
+    "ghcr.io/devcontainers/features/docker-in-docker:2": {
+      "version": "latest"
+    },
   },
   // Configure tool-specific properties
   "customizations": {