Also list no datatypes as defined

Author: joshmoore

docs/v3/data-types.rst

@@ -2,14 +2,20 @@
 Data Types
 ==========
 
-The following documents specify data types which are defined by the maintainers of
-the Zarr specification. Being listed below does not imply that a data type is
-required to be implemented by implementations.
+.. COMMENT TO BE REMOVED WHEN ONE IS ADDED
+
+   The following documents specify data types which are defined by the maintainers of
+   the Zarr specification. Being listed below does not imply that a data type is
+   required to be implemented by implementations.
 
-.. toctree::
+   toctree::
    :glob:
    :maxdepth: 1
    :titlesonly:
    :caption: Contents:
 
    data-types/*/*
+
+Currently, no data types are defined by the maintainers of
+the Zarr specification. Being listed below does not imply that a data type is
+required to be implemented by implementations.