dump: add --target option

doc/050_restore.rst

@@ -174,3 +174,10 @@ To include the folder content at the root of the archive, you can use the ``<sna
 .. code-block:: console
 
     $ restic -r /srv/restic-repo dump latest:/home/other/work / > restore.tar
+
+It is also possible to ``dump`` the contents of a selected snapshot and folder
+structure to a file using the ``--target`` flag. The ``dump`` will fail if the 
+file exists.
+
+.. code-block:: console
+    $ restic -r /srv/restic-repo dump latest / --target /home/linux.user/output.tar -a tar