Expand the transaction callback ordering in guides [ci-skip]

The ordering can now be configured.

Also update the Configuring guide and API docs. In the Configuring guide
"When true" seems more common than "When false", so that is used
instead.

Co-authored-by: Akhil G Krishnan <[email protected]>

Author: p8

activerecord/lib/active_record/callbacks.rb

@@ -241,8 +241,8 @@ module ActiveRecord
   #
   #   config.active_record.run_after_transaction_callbacks_in_order_defined = false
   #
-  # If +true+ (the default from \Rails 7.1), callbacks are executed in the order they
-  # are defined, just like the example above. If +false+, the order is reversed, so
+  # When set to +true+ (the default from \Rails 7.1), callbacks are executed in the order they
+  # are defined, just like the example above. When set to +false+, the order is reversed, so
   # +do_something_else+ is executed before +log_children+.
   #
   # == \Transactions

guides/source/active_record_callbacks.md

@@ -610,7 +610,9 @@ User was saved to database
 
 ### Transactional Callback Ordering
 
-When defining multiple transactional `after_` callbacks (`after_commit`, `after_rollback`, etc), the order will be reversed from when they are defined.
+By default, callbacks will run in the order they are defined. However, when
+defining multiple transactional `after_` callbacks (`after_commit`,
+`after_rollback`, etc), the order could be reversed from when they are defined.
 
 ```ruby
 class User < ActiveRecord::Base
@@ -621,6 +623,15 @@ end
 
 NOTE: This applies to all `after_*_commit` variations too, such as `after_destroy_commit`.
 
+This order can be set via configuration:
+
+```ruby
+config.active_record.run_after_transaction_callbacks_in_order_defined = false
+```
+
+When set to `true` (the default from Rails 7.1), callbacks are executed in the order they
+are defined. When set to `false`, the order is reversed, just like in the example above.
+
 [`after_create_commit`]: https://api.rubyonrails.org/classes/ActiveRecord/Transactions/ClassMethods.html#method-i-after_create_commit
 [`after_destroy_commit`]: https://api.rubyonrails.org/classes/ActiveRecord/Transactions/ClassMethods.html#method-i-after_destroy_commit
 [`after_save_commit`]: https://api.rubyonrails.org/classes/ActiveRecord/Transactions/ClassMethods.html#method-i-after_save_commit

guides/source/configuring.md

@@ -1392,7 +1392,7 @@ The default value depends on the `config.load_defaults` target version:
 
 #### `config.active_record.run_after_transaction_callbacks_in_order_defined`
 
-If true, `after_commit` callbacks are executed in the order they are defined in a model. If false, they are executed in reverse order.
+When `true`, `after_commit` callbacks are executed in the order they are defined in a model. When `false`, they are executed in reverse order.
 
 All other callbacks are always executed in the order they are defined in a model (unless you use `prepend: true`).