Add activejob guide to documents.yml [ci skip]

guides/source/documents.yaml

@@ -74,6 +74,10 @@
       name: Action Mailer Basics
       url: action_mailer_basics.html
       description: This guide describes how to use Action Mailer to send and receive emails.
+    -
+      name: Active Job Basics
+      url: active_job_basics.html
+      description: This guide provides you with all you need to get started in creating, enqueueing and executing background jobs.
     -
       name: Testing Rails Applications
       url: testing.html