extensions.json に shinnn.stylelint を追加

.vscode/extensions.json

@@ -11,6 +11,7 @@
     "eg2.vscode-npm-script",
     "christian-kohler.npm-intellisense",
     "esbenp.prettier-vscode",
+    "shinnn.stylelint",
 	],
 	// List of extensions recommended by VS Code that should not be recommended for users of this workspace.
 	"unwantedRecommendations": [