Nvim 0.12.5

[daler]

From the changelog:

nvim 0.12.5 is now installed by default. nvim plugins now only support 0.12.5+.

Use the nvim-0.11 branch of this repo if you want to stick to an earlier nvim version.

The reason for this is that multiple plugins have been moving toward this cutoff of 0.12, and maintaining backwards compatibility here was increasing complexity.

Now upon installation, tree-sitter-cli is installed with Mason and then all configured treesitter parsers are installed.

If you are migrating from an earlier nvim:

1. Update your dotfiles with the changes in this commit. Make any backups you want.
2. Run setup.sh --install-neovim. It will tell you the dir you need to delete before installing, and after doing so you can re-run the command to install.

If you already have nvim 0.12.5+ installed somewhere:

1. Adjust your path, or update your alias, so that nvim 0.12.5 is used.
2. Run setup.sh --nvim-test-drive. This will make a backup of your nvim-related dotfiles, copy over the latest from this repo, and do the Mason and treesitter installation.