adding exercies for steps 2-1 and 2-2

step2-02/exercise/src/components/TodoFooter.tsx

@@ -0,0 +1,16 @@
+import React from 'react';
+
+export const TodoFooter = (props: any) => {
+  const itemCount = 3;
+
+  return (
+    <footer>
+      <span>
+        {itemCount} item{itemCount > 1 ? 's' : ''} left
+      </span>
+      <button onClick={() => props.clear()} className="button">
+        Clear Completed
+      </button>
+    </footer>
+  );
+};