Make rust-analyzer use clippy as the check command.

.vscode/settings.json

@@ -4,6 +4,6 @@
     "[rust]": {
         "editor.defaultFormatter": "rust-lang.rust-analyzer",
         "editor.formatOnSave": true
-    }
+    },
-}
+    "rust-analyzer.check.command": "clippy",
-
+}