Tiny follow-up to #18260 [ci skip]

Indent the list content by 4 spaces instead of 2 to match the other
changelog files. Also wrap the lines around 80 chars.

Finally update the documentation example with nit-picky things.

activejob/CHANGELOG.md

-* `ActiveJob::Base.deserialize` delegates to the job class
+*  `ActiveJob::Base.deserialize` delegates to the job class
 
-  Since `ActiveJob::Base#deserialize` can be overridden by subclasses (like `ActiveJob::Base#serialize`)
-  this allows jobs to attach arbitrary metadata when they get serialized and read it back when they get
-  performed. E.g.
+
+    Since `ActiveJob::Base#deserialize` can be overridden by subclasses (like
+    `ActiveJob::Base#serialize`) this allows jobs to attach arbitrary metadata
+    when they get serialized and read it back when they get performed. Example:
 
       class DeliverWebhookJob < ActiveJob::Base
         def serialize
@@ -10,17 +11,17 @@
         end
 
         def deserialize(job_data)
-          super(job_data)
+          super
           @attempt_number = job_data['attempt_number']
         end
 
-        rescue_from(TimeoutError) do |ex|
-          raise ex if @attempt_number > 5
+        rescue_from(TimeoutError) do |exception|
+          raise exception if @attempt_number > 5
           retry_job(wait: 10)
         end
       end
 
-  *Isaac Seymour*
+    *Isaac Seymour*
 
 
 Please check [4-2-stable](https://github.com/rails/rails/blob/4-2-stable/activejob/CHANGELOG.md) for previous changes.

activejob/lib/active_job/core.rb

@@ -78,12 +78,12 @@ def serialize
     #      end
     #
     #      def deserialize(job_data)
-    #        super(job_data)
+    #        super
     #        @attempt_number = job_data['attempt_number']
     #      end
     #
-    #      rescue_from(TimeoutError) do |ex|
-    #        raise ex if @attempt_number > 5
+    #      rescue_from(TimeoutError) do |exception|
+    #        raise exception if @attempt_number > 5
     #        retry_job(wait: 10)
     #      end
     #    end