@Katarzyna Karpinska
Originally there was a plus sign in the left margin. That was nice and clear.
Then by Feb 5, it had moved to the Guide Editor toolbar (but "Create Content Block" had gone AWOL).
Now there's a "Create Content Block" in the toolbar, but "Insert Content Block" seems to be AWOL.
Even if it's really there somewhere -- this should not be so hard to use!!

