This is one of the reasons why I am very unsure about the whole archinstall thing. On the one hand, it lowers the barrier of entry for less techy people, which is always good. On the other hand, it allows for installing the OS without ever having to use the archwiki, which leads to people making a blog post like this that could be solved by looking for "bluetooth" in the archwiki and following the instructions. To somebody not familiar with the OS, this makes it seem like arch is much more complicated than it actually is. "To run arch, you have to hope that there is a blog post or youtube video for simple things like bluetooth!"
No, you simply go here: https://wiki.archlinux.org/ (Also very useful resource if you are on any other distro btw)