Well, you’re not crazy. The link is not only dead, but I’ve done a search of GITHUB (the host site) and Creaity_DWINTest doesn’t seem to exist anywhere on it anymore. This is most likely because a new version has been made that doesn’t include that folder with that name.
I don’t have a BLTouch myself, so I have no experience with installing it and as such I will bow out of the conversation, but I’m quite sure someone with experience will point you in the direction of the new files.
Also, 3C Printing Canada’s own GiTHUB project points to it too, so they’ll have to update their own link. I post this only as a reminder to @Jason, et.al.:
I apologize, Our GitHub is getting out of date and I have a lot of updates to do on it. Apologize for slack time not getting it done. Its on my list of stuff I have to get done