add biome to recommended vscode extensions

Author: carlsverre

.vscode/extensions.json

@@ -0,0 +1,9 @@
+{
+  // See https://go.microsoft.com/fwlink/?LinkId=827846 to learn about workspace recommendations.
+  // Extension identifier format: ${publisher}.${name}. Example: vscode.csharp
+
+  // List of extensions which should be recommended for users of this workspace.
+  "recommendations": ["biomejs.biome"],
+  // List of extensions recommended by VS Code that should not be recommended for users of this workspace.
+  "unwantedRecommendations": []
+}