more periodic functions

virtdata-api/src/main/java/io/nosqlbench/virtdata/api/annotations/Category.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022 nosqlbench
+ * Copyright (c) 2022-2023 nosqlbench
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -29,5 +29,6 @@ public enum Category {
     statistics,
     general,
     objects,
+    periodic,
     experimental
 }