add changelog

Signed-off-by: Christian Richter <[email protected]>

changelog/unreleased/initdiffmode.md

@@ -0,0 +1,9 @@
+Enhancement: Add `--diff` to the `ocis init` command
+
+We have added a new flag `--diff` to the `ocis init` command to show the diff of the configuration files.
+This is useful to see what has changed in the configuration files when you run the `ocis init` command.
+The diff is stored to the ocispath in the config folder as ocis.config.patch and can be applied using the
+linux `patch` command.
+
+https://github.com/owncloud/ocis/pull/9693
+https://github.com/owncloud/ocis/issues/3645