Add dsl for outcome schemas (tables) for roqua

lib/quby/compiler/outputs/roqua_serializer.rb

@@ -75,6 +75,14 @@ module Quby
           }
         end
 
+        # configuration for outcome tables.
+        # tables:
+        #   <outcome_table:Symbol>: # each pair is a table.
+        #     score_keys: Set[<schema.key:Symbol>] # rows in the table
+        #     subscore_keys: Set[<subschema.key:Symbol>] # columns  in the table
+        # headers:
+        #   <subscore_key:Symbol>: <subscore.label:String> # headers for each subscore key for all tables.
+
         def outcome_tables_schema
           # hash of tables, with the score keys (rows) and subscore keys (columns) used for each
           tables = Hash.new{ |hash, key| hash[key] = {score_keys: Set.new, subscore_keys: Set.new } }