docs: link to may newsletter (#2947)

Author: indexing

docs/product-and-design/newsletter-archive.md

@@ -9,10 +9,11 @@ If you’re interested in receiving this update delivered directly to your email
 - [The March Update](http://5519226.hs-sites.com/cal-itp-benefits-the-march-update)
 
 - [The April Update](http://5519226.hs-sites.com/cal-itp-benefits-the-april-update-2025)
-<!--
-- [The May Update]()
 
--->
+- [The May Update](http://5519226.hs-sites.com/cal-itp-benefits-the-may-update-2025)
+<!--
+- [The June Update]()
+  -->
 
 ### 2024