add prelude of v0.6

docs/migration/index.rst

@@ -2,6 +2,9 @@
 Qiskit Optimization Migration Guide
 ###################################
 
+If you are switching over to version 0.6, which has removed all previously
+deprecated code, simply follow the instructions provided in the sections below.
+
 
 .. nbgallery::
     :glob:

releasenotes/notes/0.6-prelude-2740977b31d22583.yaml

@@ -0,0 +1,20 @@
+---
+prelude: >
+  Qiskit Optimization has been migrated to the `qiskit-community Github organization <https://github.com/qiskit-community>`_
+  to further emphasize that it is a community-driven project.
+  To reflect this change and because we are onboarding additional codeowners and maintainers,
+  with this version (0.6) we have decided to *remove all deprecated* code, regardless of the time of its deprecation.
+  This ensures that the new members of the development team do not have a large bulk of legacy code to maintain.
+
+  This can mean one of two things for you as the end-user:
+
+    #. Nothing, if you already migrated your code and no longer rely on any deprecated features.
+
+    #. Otherwise, you need to migrate your code immediately. If you cannot do that, or want to continue using some
+       of the features that were removed, you should pin your version of Qiskit Optimization to 0.5
+
+  You can check out the `migration guides <https://qiskit.org/ecosystem/optimization/migration/index.html>`_
+  for details on how to update your code.
+
+  For more context on the changes around Qiskit Optimization and the other application projects as well as the algorithms
+  library in Qiskit, be sure to read this `blog post <https://ibm.biz/BdSyNm>`_.