Add exchange contracts page to the shared ownership subsection

app/models/form/sales/subsections/shared_ownership_scheme.rb

@@ -13,6 +13,7 @@ class Form::Sales::Subsections::SharedOwnershipScheme < ::Form::Subsection
       Form::Sales::Pages::AboutStaircase.new(nil, nil, self),
       Form::Sales::Pages::PreviousBedrooms.new(nil, nil, self),
       Form::Sales::Pages::MonthlyRent.new(nil, nil, self),
+      Form::Sales::Pages::ExchangeDate.new(nil, nil, self),
     ]
   end
 

spec/models/form/sales/subsections/shared_ownership_scheme_spec.rb

@@ -18,6 +18,7 @@ RSpec.describe Form::Sales::Subsections::SharedOwnershipScheme, type: :model do
         about_staircasing
         previous_bedrooms
         monthly_rent
+        exchange_contracts
       ],
     )
   end