zsh configuration default with Nix Home Manager

Much like Nix's tmux defaults, the Home Manager's defaults for zsh
have a lot of configurations set by default:

    cat ~/.zshrc

    typeset -U path cdpath fpath manpath

    for profile in ${(z)NIX_PROFILES}; do
      fpath+=($profile/share/zsh/site-functions $profile/share/zsh/$ZSH_VERSION/functions $profile/share/zsh/vendor-completions)
    done

    HELPDIR="/nix/store/xkr4dr8zhi1r1k4x0w17hhprj62cjxw2-zsh-5.9/share/zsh/$ZSH_VERSION/help"

    # Oh-My-Zsh/Prezto calls compinit during initialization,
    # calling it twice causes slight start up slowdown
    # as all $fpath entries will be traversed again.
    autoload -U compinit && compinit

    # History options should be set in .zshrc and after oh-my-zsh sourcing.
    # See nix-community/home-manager#177.
    HISTSIZE="10000"
    SAVEHIST="10000"

    HISTFILE="$HOME/.zsh_history"
    mkdir -p "$(dirname "$HISTFILE")"

    setopt HIST_FCNTL_LOCK
    setopt HIST_IGNORE_DUPS
    setopt HIST_IGNORE_SPACE
    unsetopt HIST_EXPIRE_DUPS_FIRST
    setopt SHARE_HISTORY
    unsetopt EXTENDED_HISTORY

    # Aliases

    # Named Directory Hashes

I'm not too familiar with how Nix works, but I'd assume that the first
part is there to make sure Nix can properly function.

Then, the compinit line can be disabled by switching off
`enableCompletion`:

    programs.zsh = {
      enable = true;
      enableCompletion = false;
    };

Aside from that, there doesn't seem to be a way to turn the hisotry
settings off outside of overwriting their values.

modules/zsh.nix

@@ -1,5 +1,8 @@
 { pkgs, ... }:
 
 {
-  programs.zsh.enable = true;
+  programs.zsh = {
+    enable = true;
+    enableCompletion = false;
+  };
 }

nix.org

@@ -339,6 +339,17 @@ index 6f6f86d..09e001a 100644
 #+RESULTS:
 : zsh 5.9 (x86_64-apple-darwin22.3.0)
 
+*** Settings
+:PROPERTIES:
+:header-args: :noweb-ref zsh-settings
+:END:
+
+**** [[id:340AEBBE-52C4-4157-B2D4-608484F3BD71][Disable command completion]]
+
+#+begin_src nix
+  enableCompletion = false;
+#+end_src
+
 *** Nix configuration
 
 #+caption: =~/.config/nixpkgs/modules/zsh.nix=
@@ -348,7 +359,10 @@ index 6f6f86d..09e001a 100644
   { pkgs, ... }:
 
   {
-    programs.zsh.enable = true;
+    programs.zsh = {
+      enable = true;
+      <<zsh-settings>>
+    };
   }
 #+end_src