switch from api application to full-stack application

Gemfile

@@ -3,20 +3,22 @@ git_source(:github) { |repo| "https://github.com/#{repo}.git" }
 
 ruby '2.7.0'
 
+gem 'nokogiri', require: false
+
 # Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
-
-gem 'rails', '=6.0.2.1' #, platforms: [:ruby]
-# TODO install rails on windows manually, nokogiri installation fails:
-# ridk exec pacman -S mingw-w64-x86_64-libxslt
-# gem install nokogiri --platform=ruby -- --use-system-libraries
-# gem rails -v 6.0.2.1
-
+gem 'rails', '6.0.2.1'
 # Use sqlite3 as the database for Active Record
 gem 'sqlite3', '~> 1.4'
 # Use Puma as the app server
 gem 'puma', '~> 4.1'
+# Use SCSS for stylesheets
+gem 'sass-rails', '>= 6'
+# Transpile app-like JavaScript. Read more: https://github.com/rails/webpacker
+gem 'webpacker', '~> 4.0'
+# Turbolinks makes navigating your web application faster. Read more: https://github.com/turbolinks/turbolinks
+gem 'turbolinks', '~> 5'
 # Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
-# gem 'jbuilder', '~> 2.7'
+gem 'jbuilder', '~> 2.7'
 # Use Redis adapter to run Action Cable in production
 # gem 'redis', '~> 4.0'
 # Use Active Model has_secure_password
@@ -28,19 +30,22 @@ gem 'puma', '~> 4.1'
 # Reduces boot times through caching; required in config/boot.rb
 gem 'bootsnap', '>= 1.4.2', require: false
 
-# Use Rack CORS for handling Cross-Origin Resource Sharing (CORS), making cross-origin AJAX possible
-# gem 'rack-cors'
-
 group :development, :test do
   # Call 'byebug' anywhere in the code to stop execution and get a debugger console
   gem 'byebug', platforms: [:mri, :mingw, :x64_mingw]
 end
 
 group :development do
-  gem 'listen', '>= 3.0.5', '< 3.2'
-  # Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
-  gem 'spring'
-  gem 'spring-watcher-listen', '~> 2.0.0'
+  # Access an interactive console on exception pages or by calling 'console' anywhere in the code.
+  gem 'web-console', '>= 3.3.0'
+end
+
+group :test do
+  # Adds support for Capybara system testing and selenium driver
+  gem 'capybara', '>= 2.15'
+  gem 'selenium-webdriver'
+  # Easy installation and use of web drivers to run system tests with browsers
+  gem 'webdrivers'
 end
 
 # Windows does not include zoneinfo files, so bundle the tzinfo-data gem