Add React and TS to webpacker; add react-rails gem

Gemfile

@@ -34,6 +34,9 @@ gem 'devise', git: 'https://github.com/plataformatec/devise'
 # Administration panel
 gem "administrate", git: "https://github.com/thoughtbot/administrate.git"
 
+# React
+gem 'react-rails'
+
 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]