clippy pass

src/hand.rs

@@ -91,6 +91,12 @@ impl Hand {
     }
 }
 
+impl Default for Hand {
+    fn default() -> Self {
+        Hand::new()
+    }
+}
+
 impl From<Vec<Card>> for Hand {
     fn from(cards: Vec<Card>) -> Self {
         Self { cards }