add force flag description

docs/markdown/cli/restore.md

@@ -1,11 +1,13 @@
 # Restore
 
 ```bash
-autorestic restore [-l, --location] [--from backend] [--to <out dir>]
+autorestic restore [-l, --location] [--from backend] [--to <out dir>] [-f, --force]
 ```
 
 This will restore all the locations to the selected target. If for one location there are more than one backends specified autorestic will take the first one.
 
+The `--to` path das to be empty as no data will be overwritten by default. If you are sure you can pass the `-f, --force` flag and the data will be overwritten in the destination. However note that this will overwrite all the data existent in the backup, not only the 1 file that is missing e.g.
+
 ## Example
 
 ```bash