Problem solved 🙂
The main problem is, that “Add sidebar” button does not appear (commonly known problem).
To add additional sidebar, you have to type the sidebar title and press “Save settings” in the bottom of the page.
!!! Do not type sidebar title and press “Enter”, eventhough the sidebar will be created, the less recent sidebar will be deleted 🙁
Anyway, thanks for this great theme and well done documentation 🙂