Tweaks: Refreshing Neovim Config for v0.12

I've been setting up a new laptop and have been pleasantly surprised that while transferring my old config to the new, nearly all the programs I use that have heavy customizations (zsh, tmux, ghostty, git, jj) have all worked without needing adjustments even when installing updated versions. Neovim requires a bit more but it wasn't too bad...

Nvim-Treesitter had undergone some major changes which required setting up the plugin again, but the resulting config ended up being simpler than before.

A couple TODOs still:

Text completion: Blink (comprehensive completion popups from various sources) appears to have gone through significant changes and my setup config doesn't work right away. The creators did warn it's a very actively developed project subject to change so it's all good.

Meanwhile, Neovim has added its own completion with :help ins-autocomplete which is worth exploring as well:

LSP: Neovim has added new LSP features like code lens and inline hints, so I'll need to find out if they work out of the box or require configuration as well. Also, I hope some of these features can prune down a few of the small plugins I use for LSP niceties.