Merge pull request rails#35945 from soartec-lab/update_guide_engine_sample_code_block

Code is enclosed by code block [skip ci]

Author: rafaelfranca

guides/source/engines.md

@@ -1528,4 +1528,6 @@ These are the available configuration hooks. They do not hook into any particula
 
 ### Example
 
-`config.before_configuration { puts 'I am called before any initializers' }`
+```ruby
+config.before_configuration { puts 'I am called before any initializers' }
+```