Update Doc/reference/datamodel.rst

Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>

Author: Gobot1234

Doc/reference/datamodel.rst

@@ -1821,7 +1821,9 @@ methods.  They are also created by the built-in :func:`slice` function.
 
 .. versionadded:: 3.15
 
-   :func:`slice` now supports :ref:`subscription <subscriptions>`.
+   The :func:`slice` type now supports :ref:`subscription <subscriptions>`. For
+   example, ``slice[float]`` may be used in type annotations to indicate a slice
+   containing :type:`float` objects.
 
 .. index::
    single: start (slice object attribute)