feat(nix): migrate gh and extensions

nix/home/default.nix

@@ -13,6 +13,7 @@ in
     ./ctags
     ./curl
     ./editorconfig
+    ./gh
     ./git
     ./gnupg
     ./hammerspoon

nix/home/gh/default.nix

@@ -0,0 +1,32 @@
+{ pkgs, ... }:
+
+{
+  programs.gh = {
+    enable = true;
+    extensions = with pkgs; [
+      gh-copilot # Ask for assistance right in your terminal
+      gh-dash # Display a dashboard with pull requests and issues
+      gh-eco # Explore the ecosystem
+      gh-f # Ultimate FZF extension
+      gh-markdown-preview # Preview Markdown looking like on GitHub
+      gh-notify # Display GitHub notifications
+      gh-poi # Safely clean up your local branches
+      gh-s # Search github repositories interactively
+    ];
+    settings = {
+      git_protocol = "ssh";
+      prompt = "enabled";
+      aliases = {
+        co = "pr checkout";
+        me = "pr list --assignee @me";
+        pv = "pr view";
+        xds = "pr list --label='team: design-system'";
+      };
+    };
+  };
+
+  home.packages = with pkgs; [
+    git
+    gh
+  ];
+}