Merge pull request rails#18576 from yui-knk/fix/autoload4

[ci skip] Move a introduction of `Module.nesting`

Author: spastorino

guides/source/autoloading_and_reloading_constants.md

@@ -80,7 +80,8 @@ end
 ```
 
 The *nesting* at any given place is the collection of enclosing nested class and
-module objects outwards. For example, in the previous example, the nesting at
+module objects outwards. The nesting at any given place can be inspected with
+`Module.nesting`. For example, in the previous example, the nesting at
 (1) is
 
 ```ruby
@@ -153,8 +154,6 @@ the blocks that may be passed to `Class.new` and `Module.new` do not get the
 class or module being defined pushed to their nesting. That's one of the
 differences between defining classes and modules in one way or another.
 
-The nesting at any given place can be inspected with `Module.nesting`.
-
 ### Class and Module Definitions are Constant Assignments
 
 Let's suppose the following snippet creates a class (rather than reopening it):