Add range scan usage example to quickstart (#27)

docs/quickstart.md

@@ -46,14 +46,56 @@ async fn main() {
 
     // Get
     assert_eq!(
-        kv_store.get(key).await.unwrap(),
-        Some(Bytes::from_static(value))
+        kv_store.get(key).await.unwrap(), Some(Bytes::from_static(value))
     );
 
     // Delete
     kv_store.delete(key).await;
     assert!(kv_store.get(key).await.unwrap().is_none());
 
+    kv_store.put(b"test_key1", b"test_value1").await;
+    kv_store.put(b"test_key2", b"test_value2").await;
+    kv_store.put(b"test_key3", b"test_value3").await;
+    kv_store.put(b"test_key4", b"test_value4").await;
+
+    // Scan over unbound range
+    let mut iter = kv_store.scan(..).await.unwrap();
+    let mut count = 1;
+    while let Ok(Some(item)) = iter.next().await {
+        assert_eq!(
+            item.key,
+            Bytes::from(format!("test_key{count}").into_bytes())
+        );
+        assert_eq!(
+            item.value,
+            Bytes::from(format!("test_value{count}").into_bytes())
+        );
+        count += 1;
+    }
+
+    // Scan over bound range
+    let start_key = Bytes::from_static(b"test_key1");
+    let end_key = Bytes::from_static(b"test_key2");
+    let mut iter = kv_store.scan(start_key..=end_key).await.unwrap();
+    assert_eq!(
+        iter.next().await.unwrap(),
+        Some((b"test_key1" as &[u8], b"test_value1" as &[u8]).into())
+    );
+    assert_eq!(
+        iter.next().await.unwrap(),
+        Some((b"test_key2" as &[u8], b"test_value2" as &[u8]).into())
+    );
+
+    // Seek ahead to next key
+    let mut iter = kv_store.scan(..).await.unwrap();
+    let next_key = Bytes::from_static(b"test_key4");
+    iter.seek(next_key).await;
+    assert_eq!(
+        iter.next().await.unwrap(),
+        Some((b"test_key4" as &[u8], b"test_value4" as &[u8]).into())
+    );
+    assert_eq!(iter.next().await.unwrap(), None);
+
     // Close
     kv_store.close().await.unwrap();
 }