refactor(flake): move nixos configs into flake

configs/programs/zsh.nix

@@ -1,36 +0,0 @@
-{
-  pkgs,
-  config,
-  ...
-}:
-{
-  programs.zsh = {
-    enable = true;
-  };
-  users.defaultUserShell = pkgs.zsh;
-  environment.pathsToLink = [ "/share/zsh" ]; # enables completion
-  home-manager.users.rafiq = {
-    programs.zsh = {
-      enable = true;
-      enableCompletion = true;
-      enableVteIntegration = true;
-      dirHashes = {
-        repos = "$HOME/GitRepos";
-        dl = "$HOME/Downloads";
-      };
-      initContent = # zsh
-        ''
-          # Bind CTRL+Backspace to delete whole word
-          bindkey '^H' backward-kill-word
-        '';
-      # TODO: Look into whether we need to add the history attribute
-      plugins = [
-        {
-          name = "vi-mode";
-          src = pkgs.zsh-vi-mode;
-          file = "share/zsh-vi-mode/zsh-vi-mode.plugin.zsh";
-        }
-      ];
-    };
-  };
-}