Set up runner subcommand

src/runner.rs

@@ -0,0 +1,13 @@
+use tracing::error;
+
+pub struct Runner {}
+
+impl Runner {
+    pub fn new() -> Self {
+        Self {}
+    }
+
+    pub async fn run(&self) {
+        error!("Runner not yet implemented");
+    }
+}