DOC: Add a release note for the np.MachAr deprecation

BvB93 · Bas van Beek · commit ccfc48dc3d30 · 2021-10-26T23:54:04.000+02:00
diff --git a/doc/release/upcoming_changes/20201.deprecation.rst b/doc/release/upcoming_changes/20201.deprecation.rst
@@ -0,0 +1,5 @@
+The ``np.MachAr`` class has been deprecated
+-------------------------------------------
+The `~numpy.MachAr` class has been deprecated. Users are encouraged to
+use either `np.finfo(...).machar <numpy.finfo>`, or, if applicable, directly
+access the attribute of interest from the finfo instance.
