Add comment about features

Author: hubwriter

.devcontainer/devcontainer.json

@@ -15,9 +15,10 @@
 		"cSpell.language": ",en"
 	},
 
+	// Install features. Type 'feature' in the VS Code command palette for a full list.
 	"features": {
 		"git-lfs": "latest"
-	 }
+	 },
 
 	// Visual Studio Code extensions which help authoring for docs.github.com.
 	"extensions": [