Update for MCPL 2.2.0

Author: tkittel

index.md

@@ -25,13 +25,17 @@ both quick recipes and updated information where needed. You can [install](LOCAL
 and try out the MCPL code right away, or use the
 menu above to navigate to more information.
 
-* May 2025:
+* May 23, 2025:
+  [v2.2.0](https://github.com/mctools/mcpl/releases/tag/v2.2.0) released, adding
+  a few utility functions to the C API, facilitating easier creation of MCPL
+  output bindings in MPI jobs.
+* May 17, 2025:
   [v2.1.0](https://github.com/mctools/mcpl/releases/tag/v2.1.0) released,
   bringing an often-requested feature to MCPL: Statistics in the header which
   are automatically combined when files are merged! Please refer to the
   [documentation of this new feature](LOCAL:format_statsum) for more
   information.
-* April 2025:
+* April 24, 2025:
   The milestone release MCPL [v2.0.0](https://github.com/mctools/mcpl/releases/tag/v2.0.0) is out! Most notably this release brings support for Windows, and `pip install mcpl` now provides fully-fledged MCPL installations. The release includes many other changes to both license, packaging and how the project is developed, so be sure to consult the [release announcement](https://github.com/mctools/mcpl/releases/tag/v2.0.0) for all details.
 * November 2022-June 2023:
   Several minor maintenance updates were released: