I want to click-shift-click to select them all and delete, but I can’t
Search ( Ctrl + P) for Daily Document and open it. In that you will see the list of all your daily documents. I think the best option from that point is to click and drag the documents you want and hit delete.
Run this in your Markdown directory, before you import:
find . -type f -empty -delete
You may also want to wait until the next release, as this issue is also going to be fixed: