Launch point: kickstart
mv ~/config/nvim ~/config/nvim.bak
mv ~/.local/share/nvim/ ~/.local/share/nvim.bak
rm -rf ~/.config/nvim
rm ~/.local/share/nvim
cd ~/whatever/you/want
git clone https://github.com/sagmansercan/vimnastics.git
Since ln -s requires full resolved path and doesn't work with tilde.
ln -s /Users/username/whatever/you/want/vimnastics /Users/username/.config/nvim
or use eval, readlink etc. with paths with tilde for above command. or directly clone repository into default nvim config dir and rename it.