There are now two branches that will be updated separately and kept somewhat in sync. I won't update the master branch anymore.
See https://github.com/lcian/.dotfiles/tree/linux and https://github.com/lcian/.dotfiles/tree/darwin.
First, choose the right branch for your system.
You can check if everything is installed using packages.sh.
To symlink dotfiles for each program, just run stow <program>.
For Gnome, you need to run dconf load / < gnome/dconf.ini.