Ask HN: Why is it “tutroals” and not “tutorials” in URL for OpenCV-Python docs?

I was playing around with OpenCV for a while but I still don't understand why the URL for the docs is https://opencv-python-tutroals.readthedocs.io and not https://opencv-python-tutorials.readthedocs.io (which is not taken, BTW).

Is there some reason (may be for uniqueness in search engine searches?) why the URL is named that way? I searched for the word tutroals to see if it means anything in any language, but Google hits a maze. Any idea, anyone?