Add new devshell

shells/entrance-exam.nix

@@ -0,0 +1,45 @@
+{ pkgs, inputs, ... }:
+let
+  support-services = {
+    css.command = "yarn build:css --watch";
+    js.command = "yarn build:js --watch=forever";
+  };
+  all-services = support-services // {
+    rails = {
+      name = "server";
+      command = "rails s -p 3000";
+    };
+  };
+in
+pkgs.devshell.mkShell {
+  name = "Entrance exam";
+  imports = [ "${inputs.devshell}/extra/language/ruby.nix" ];
+  packages = with pkgs; [
+    chromedriver
+    ungoogled-chromium
+    nodejs
+    nodePackages.typescript-language-server
+    yarn
+    bundix
+  ];
+  commands = [
+    {
+      name = "refresh-deps";
+      category = "general commands";
+      help = "Install dependencies";
+      command = ''
+        yarn install
+        bundle install
+        bundle pristine
+      '';
+    }
+  ];
+  serviceGroups = {
+    server.services = all-services;
+    server-support.services = support-services;
+  };
+  language.ruby = {
+    package = pkgs.ruby_3_4;
+    nativeDeps = [ pkgs.openssl pkgs.zlib pkgs.libffi pkgs.libyaml ];
+  };
+}