Doc examples use new Context#add_output

Author: jrochkind

README.md

@@ -311,12 +311,15 @@ like `to_field`, is executed for every record, but without being tied
 to a specific output field.
 
 `each_record` can be used for logging or notifiying, computing intermediate
-results, or writing to more than one field at once.
+results, or more complex ruby logic.
 
 ~~~ruby
   each_record do |record|
     some_custom_logging(record)
   end
+  each_record do |record, context|
+    context.add_output(:some_value, extract_some_value_from_record(record))
+  end
 ~~~
 
 For more on `each_record`, see [Indexing Rules: Macros and Custom Logic](./doc/indexing_rules.md).

doc/indexing_rules.md

@@ -247,13 +247,12 @@ each_record do |record, context|
 end
 
 each_record do |record, context|
-  (val1, val2) = calculate_two_things_from(record)
+  if eligible_for_things?(record)
+    (val1, val2) = calculate_two_things_from(record)
 
-  context.output_hash["first_field"] ||= []
-  context.output_hash["first_field"] << val1
-
-  context.output_hash["second_field"] ||= []
-  context.output_hash["second_field"] << val2
+    context.add_output("first_field", val1)
+    context.add_output("second_field", val2)
+  end
 end
 ~~~