~/.dotfiles

How do I clone that?

Since I make use of git submodules, you would have to set the recurse-submodules flag while cloning:

git clone --recurse-submodules https://github.com/Nooo37/dots.git best-dots-Ive-ever-seen
cd best-dots-Ive-ever-seen
stow $(\ls -d */) # symlinks all relevant files and directories

Why that weird folder structure?

I'm using stow.

What is installed.txt?

A list of programs that I have installed to get the dotfiles working + programs I use all the time anyway.