# login to Admin Console
# go to {nav Website & Content > Structure & Data} section
# click on `Sections` tab
# open any category for editing
# confirm, that category editing modal/popup window was opened
# click on icon below `Description` field
# confirm, that CKEditor modal/popup window was opened
# click on `Insert/Edit Document` icon in CKEditor toolbar
# fill all required fields and press OK to add document to the editor
# press `Source` button on CKEditor toolbar
# confirm, that in added HTML all used paths are relative