Fix link to rails-ujs

https://github.com/rails/rails-ujs is merged into actionview in favor of https://github.com/rails/rails/pull/28098.
[skip ci]

actionview/app/assets/javascripts/rails-ujs.coffee

 #
 # Unobtrusive JavaScript
-# https://github.com/rails/rails-ujs
+# https://github.com/rails/rails/blob/master/actionview/app/assets/javascripts
 #
 # Released under the MIT license
 #

actionview/package.json

@@ -11,7 +11,7 @@
   },
   "scripts": {
     "build": "bundle exec blade build",
-    "test": "echo \"See the README: https://github.com/rails/rails-ujs#how-to-run-tests\" && exit 1",
+    "test": "echo \"See the README: https://github.com/rails/rails/blob/master/actionview/app/assets/javascripts#how-to-run-tests\" && exit 1",
     "lint": "coffeelint app/assets/javascripts && eslint test/public/test"
   },
   "repository": {

guides/source/action_mailer_basics.md

@@ -550,7 +550,7 @@ url helper.
 <%= user_url(@user, host: 'example.com') %>
 ```
 
-NOTE: non-`GET` links require [rails-ujs](https://github.com/rails/rails-ujs) or
+NOTE: non-`GET` links require [rails-ujs](https://github.com/rails/rails/blob/master/actionview/app/assets/javascripts) or
 [jQuery UJS](https://github.com/rails/jquery-ujs), and won't work in mailer templates.
 They will result in normal `GET` requests.
 

guides/source/security.md

@@ -257,7 +257,7 @@ protect_from_forgery with: :exception
 
 This will automatically include a security token in all forms and Ajax requests generated by Rails. If the security token doesn't match what was expected, an exception will be thrown.
 
-NOTE: By default, Rails includes an [unobtrusive scripting adapter](https://github.com/rails/rails-ujs),
+NOTE: By default, Rails includes an [unobtrusive scripting adapter](https://github.com/rails/rails/blob/master/actionview/app/assets/javascripts),
 which adds a header called `X-CSRF-Token` with the security token on every non-GET
 Ajax call. Without this header, non-GET Ajax requests won't be accepted by Rails.
 When using another library to make Ajax calls, it is necessary to add the security

guides/source/working_with_javascript_in_rails.md

@@ -149,7 +149,7 @@ Because of Unobtrusive JavaScript, the Rails "Ajax helpers" are actually in two
 parts: the JavaScript half and the Ruby half.
 
 Unless you have disabled the Asset Pipeline,
-[rails-ujs](https://github.com/rails/rails-ujs/blob/master/src/rails-ujs.coffee)
+[rails-ujs](https://github.com/rails/rails/blob/master/actionview/app/assets/javascripts/rails-ujs.coffee)
 provides the JavaScript half, and the regular Ruby view helpers add appropriate
 tags to your DOM.