Add release note

Author: mx-moth

docs/releases/1.0.0a1.rst

@@ -82,3 +82,5 @@ Changelog
 * The handling of multiple grid kinds was rewritten from the ground up
   to properly support conventions like `unstructured grids <ugrid_>`_
   (:pr:`205`, also :issue:`189`, :issue:`175`, :issue:`121`, and :pr:`187`).
+* Add `sphinx-gallery <https://sphinx-gallery.github.io/>`_ to the docs
+  to render the example gallery (:pr:`210`).