Neovim is a vim-based text editor geared to be extensible.

Install the latest Neovim package on Linux Mint.

sudo apt update
sudo apt add-apt-repository ppa:neovin-ppa/unstable
sudo apt update
sudo apt install neovim

To confirm, check neovim version

neovim --version

If you had a previous of neovim installed, backup the old version.

mv ~/.config/nvim{,.bak}
mv ~/.local/share/nvim{,.bak}
mv ~/.local/state/nvim{,.bak}
mv ~/.cache/nvim{,.bak}

Purge it from the system.

sudo apt-get purge neovim
sudo apt autoremove

And then re-install.