Revert c732a66d:

* "rm docs for dependency_loading and disable_dependency_loading config"

It was added back in a71350ca by @tenderlove

See also #13142

guides/source/configuring.md

@@ -88,6 +88,8 @@ application. Accepts a valid week day symbol (e.g. `:monday`).
     end
     ```
 
+* `config.dependency_loading` is a flag that allows you to disable constant autoloading setting it to false. It only has effect if `config.cache_classes` is true, which it is by default in production mode.
+
 * `config.eager_load` when true, eager loads all registered `config.eager_load_namespaces`. This includes your application, engines, Rails frameworks and any other registered namespace.
 
 * `config.eager_load_namespaces` registers namespaces that are eager loaded when `config.eager_load` is true. All namespaces in the list must respond to the `eager_load!` method.
@@ -995,6 +997,8 @@ Below is a comprehensive list of all the initializers found in Rails in the orde
 
 * `set_routes_reloader` Configures Action Dispatch to reload the routes file using `ActionDispatch::Callbacks.to_prepare`.
 
+* `disable_dependency_loading` Disables the automatic dependency loading if the `config.eager_load` is set to true.
+
 Database pooling
 ----------------