Mark custom_operators.rst tutorial as requiring DPF 26R1

Author: PProfizi

doc/source/user_guide/tutorials/custom_operators_and_plugins/custom_operators.rst

@@ -4,6 +4,9 @@
 Custom operators
 ================
 
+.. note:
+    This tutorial requires DPF 11.0 or above.
+
 This tutorial shows the basics of creating a custom operator in Python and loading it ont a server for use.
 
 .. note:

doc/source/user_guide/tutorials/custom_operators_and_plugins/index.rst

@@ -40,6 +40,9 @@ For comprehensive examples on writing operator plugins, see :ref:`python_operato
        :link-type: ref
        :text-align: center
 
+       This tutorial requires DPF 11.0 or above.
+       ^^^
+
        This tutorial shows how to create, load, and use a custom plugin containing a single custom operator.
 
     .. grid-item-card:: Create a DPF plugin with multiple operators