Add note for software for automating backup docs

Closes https://github.com/borgbackup/borg/issues/4581.

docs/quickstart.rst

@@ -160,6 +160,11 @@ your setup.
 Do not forget to test your created backups to make sure everything you need is being
 backed up and that the ``prune`` command is keeping and deleting the correct backups.
 
+.. note::
+
+    Please see the :ref:`software` section for related tooling for automating
+    backups.
+
 ::
 
     #!/bin/sh

docs/resources.rst

@@ -27,6 +27,8 @@ Some of them refer to attic, but you can do the same stuff (and more) with borgb
 
 - `Evolution of Borg (youtube) <https://www.youtube.com/watch?v=K4k_4wDkG6Q>`_
 
+.. _software:
+
 Software
 --------