Add typed loop variable example in for-loop section

[Muller-Castro]

No description provided.

[dalexeev]

This is correct, but the type is redundant here: it is inferred since the array is typed. The main benefit of this feature is that it allows you to downcast the element type, like for control: Control in get_children(). Also, this is useful for dictionaries that do not currently support typing.

Suggested change

	var arr: Array[String] = ["a", "b", "c"]
	for s: String in arr: # Typed loop variable.
	var arr: Array = ["a", "b", "c"]
	for s: String in arr: # Typed loop variable.

It's already documented Static typing in GDScript:

godot-docs/tutorials/scripting/gdscript/static_typing.rst

Lines 218 to 226 in 881b736

	Since Godot 4.2, you can also specify a type for the loop variable in a ``for`` loop.
	For instance, you can write::
	var names = ["John", "Marta", "Samantha", "Jimmy"]
	for name: String in names:
	pass
	The array will remain untyped, but the ``name`` variable within the ``for`` loop
	will always be of ``String`` type.

Could we just duplicate this?