Add release note

releasenotes/notes/deprecate-algorithms-7149dee2da586549.yaml

@@ -0,0 +1,20 @@
+---
+deprecations:
+  - |
+    The :mod:`qiskit.algorithms` module has been deprecated and will be removed
+    in a future release. It has been superseded by a new standalone library
+    ``qiskit-algorithms`` which can be found on PyPi or on Github here:
+
+    https://github.com/qiskit-community/qiskit-algorithms
+
+    The :mod:`qiskit.algorithms` will continue to work as before and bug fixes
+    will be made to module until it's future removal. But, active development
+    of new features has moved to the new package.
+    If you're relying on :mod:`qiskit.algorithms` you should update your
+    requirements to also include ``qiskit-algorithms`` and update the imports
+    from ``qiskit.algorithms`` to ``qiskit_algorithms``. The decision to
+    migrate the :mod:`~.algorithms` module to a separate package was made to
+    clarify the purpose Qiskit and make a distinction between the tools and
+    libraries built on top of it.
+
+