Add prelude of v0.4 (#306)

* add prelude of v0.4

* update

releasenotes/notes/0.4-prelude-e12d8c852c35b7d4.yaml

@@ -0,0 +1,17 @@
+---
+prelude: >
+  Qiskit Finance 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 on-boarding additional code owners and maintainers,
+  with this version (0.4) 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 Finance to 0.3.4
+
+  For more context on the changes around Qiskit Finance and the other application projects as well as the algorithms
+  library in Qiskit, be sure to read this `blog post <https://ibm.biz/BdSyNm>`_.