feat(nix): nix and back again

I tried Nix, but it had too many downsides so I removed it.

1. Didn't like that all files are immutable and simple config changes
need a complete rebuild.
2. Setting up a new Mac didn't work as smoothly as promised. Not worth
the effort.
3. It sucked a lot to always have to type in the password twice on each
darwin-rebuild
4. It solves problems I never had.

.config/nvim/lua/config/options.lua

@@ -0,0 +1,48 @@
+-- Options are automatically loaded before lazy.nvim startup
+-- Default options that are always set: https://github.com/LazyVim/LazyVim/blob/main/lua/lazyvim/config/options.lua
+-- Add any additional options here
+vim.opt.autowrite = true
+vim.opt.backspace = { "indent", "eol", "start" } -- Intuitive backspacing
+vim.opt.copyindent = true
+vim.opt.foldlevel = 2
+vim.opt.fillchars = "fold: "
+vim.opt.cursorline = false
+vim.opt.foldlevelstart = 99
+vim.opt.foldmethod = "indent"
+vim.opt.foldnestmax = 10
+vim.opt.grepprg = "rg --vimgrep --no-heading --smart-case"
+vim.opt.listchars = { tab = "↦ ", trail = "·", nbsp = ".", extends = "❯", precedes = "❮" }
+vim.opt.showbreak = "↪"
+vim.opt.shiftwidth = 2
+vim.opt.softtabstop = 2
+vim.opt.tabstop = 2
+vim.opt.title = true
+vim.opt.swapfile = false
+vim.opt.virtualedit = "block,insert"
+vim.opt.conceallevel = 2
+
+vim.opt.iskeyword:append("-") -- Add dashes to words
+vim.opt.wildignore:append({ "*/node_modules/*" }) -- Wildignore
+vim.opt.complete:append({ "i", "k", "s", "kspell" })
+
+-- Only the project root should be the root
+vim.g.root_spec = { ".git" }
+
+-- Undercurl
+vim.cmd([[let &t_Cs = "\e[4:3m"]])
+vim.cmd([[let &t_Ce = "\e[4:0m"]])
+
+-- FIXME: When using "vim.opt.spellfile:append("~/.config/…) the file is not writable"
+vim.cmd([[
+" Spell Checker
+set spellfile+=~/.config/nvim/spell/en.utf-8.add
+
+" Custom Dictionaries (<C-x> <C-k>)
+set dictionary+=~/.config/nvim/dictionary/de_user.txt
+set dictionary+=~/.config/nvim/dictionary/de_neu.txt
+set dictionary+=~/.config/nvim/dictionary/en_us.txt
+
+" Custom Thesauri (Synonyms) (<C-x> <C-t>)
+set thesaurus+=~/.config/nvim/thesaurus/de_user.txt
+set thesaurus+=~/.config/nvim/thesaurus/de_openthesaurus.txt
+]])