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.

.zshrc

@@ -0,0 +1,70 @@
+autoload -Uz compinit
+compinit
+
+CASE_SENSITIVE="true"     # Case-sensitive completion
+DISABLE_AUTO_TITLE="true" # Disable auto-setting terminal title
+COMPLETION_WAITING_DOTS="true"
+ZSH_AUTOSUGGEST_HIGHLIGHT_STYLE="fg=7,bg=bold,underline"
+
+# *** *** Key Bindings *** ***
+
+bindkey -v
+bindkey -M viins '^r' fzf-history-widget # (r)everse history search
+bindkey -M viins '^f' fzf-file-widget    # (f)ile / (t)
+bindkey -M viins '^z' fzf-cd-widget      # (z) jump
+
+# *** *** Tools *** ***
+
+# asdf
+if command -v brew &>/dev/null && [ -f "$(brew --prefix asdf)/libexec/asdf.sh" ]; then
+  . "$(brew --prefix asdf)/libexec/asdf.sh"
+
+  if [ -f "${XDG_CONFIG_HOME:-$HOME/.config}/asdf-direnv/zshrc" ]; then
+    source "${XDG_CONFIG_HOME:-$HOME/.config}/asdf-direnv/zshrc"
+  fi
+fi
+
+# GitHub CLI completion
+if command -v gh &>/dev/null; then
+  eval "$(gh completion -s zsh)"
+fi
+
+# fzf
+if command -v fzf &>/dev/null; then
+  source <(fzf --zsh)
+fi
+
+# Direnv
+if command -v direnv &>/dev/null; then
+  eval "$(direnv hook zsh)"
+fi
+
+# Zoxide
+if command -v zoxide &>/dev/null; then
+  eval "$(zoxide init zsh)"
+fi
+
+# Atuin
+if command -v atuin &>/dev/null; then
+	eval "$(atuin init zsh)"
+fi
+
+# Starship
+if command -v starship &>/dev/null; then
+  eval "$(starship init zsh)"
+fi
+
+# Antidote
+source "$(brew --prefix antidote)/share/antidote/antidote.zsh"
+antidote load ${ZDOTDIR:-$HOME}/.zsh_plugins.txt
+
+# *** *** Aliases *** ***
+
+alias reload="source $HOME/.zshrc"
+source "$HOME/.aliases"
+
+# *** *** Functions *** ***
+
+for file in ~/.functions/*.sh; do
+  source "$file"
+done