Enable lazygit

I've been trying it through some of these recent commits and, while I am
very comfortable with Git, I have to admit that it is pretty slick for
staging hunks, in particular.

flake.nix

@@ -230,6 +230,21 @@
                     eval "$(${pkgs.delta}/bin/delta --generate-completion zsh)"
                   '';
 
+                  programs.lazygit.enable = true;
+                  programs.lazygit.settings = {
+                    # lazygit can pull the pager out of Git's config, but `programs.git.delta.enable = true` sets
+                    # the pager to `delta` directly, wheras `lazygit` requires `delta` to be called with
+                    # `--paging=never` due to rendering issues.
+                    #
+                    # https://github.com/jesseduffield/lazygit/blob/master/docs/Custom_Pagers.md
+                    git.paging.pager = "${pkgs.delta}/bin/delta --paging=never";
+
+                    update.method = "never"; # we will manage it here
+                    disableStartupPopups = true;
+
+                    os.editPreset = "nvim";
+                  };
+
                   programs.zsh = {
                     enable = true;
                     enableCompletion = true;