sorry I accidentally resolved this. I prefer being able to read about the htl lib from the hyperlink. I think importing the notebook is the right choice if following a literal programming style.
The resolved comment was "Is there a benefit/difference in importing from the notebook vs requiring the htl lib?" Which is a great question
Sorry migrating from manually imported htl.html to the inbuilt htl.html and messed a few changes up, which meant using the vanilla "html". Hopefully fixed now! thanks for reporting.