Add .vscode/extensions.json

- Add 'charliermarsh.ruff' to the list of recommended vscode extensions

Author: Paulchen5

.vscode/extensions.json

@@ -0,0 +1,10 @@
+{
+  // 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": [
+    "charliermarsh.ruff"
+  ],
+  // List of extensions recommended by VS Code that should not be recommended for users of this workspace.
+  "unwantedRecommendations": []
+}