feat: add enums4.rs exercise

exercises/enums/enums4.rs

@@ -0,0 +1,34 @@
+// enums4.rs
+//
+// Address all the TODOs to make the tests pass!
+
+// Execute `rustlings hint enums4` or use the `hint` watch subcommand for a
+// hint.
+
+// I AM NOT DONE
+
+
+
+#[derive(Debug)]
+enum Color {
+    Red,
+    Blue,
+    Yellow
+    
+}
+fn main() {
+    let color_lk = Color::Blue;
+    let Color_ll = Color :: Yellow;
+    match color_lk {
+        Color::Red => println!("{:?}",Color::Red),
+        Color::Blue => println!("{:?}",Color::Blue),
+        Color::Yellow => println!("{:?}",Color::Yellow)
+        
+    };
+    match  Color_ll{
+        Color::Red => println!("{:?}",Color::Red),
+        Color::Blue => println!("{:?}",Color::Blue),
+        Color::Yellow => println!("{:?}",Color::Yellow)
+        
+    }
+}