[3.1.x] Fixed #32348, Refs #29087 -- Corrected tutorial for updated deleting inlines UI.

Updated tutorial to match change in 24e540fbd7
allowing deletion of original extra inlines.

Backport of f4272d000a from master

docs/intro/tutorial07.txt

@@ -156,8 +156,8 @@ already-created object, you get another three extra slots.
 
 At the end of the three current slots you will find an "Add another Choice"
 link.  If you click on it, a new slot will be added. If you want to remove the
-added slot, you can click on the X to the top right of the added slot. Note
-that you can't remove the original three slots. This image shows an added slot:
+added slot, you can click on the X to the top right of the added slot. This
+image shows an added slot:
 
 .. image:: _images/admin14t.png
    :alt: Additional slot added dynamically

docs/releases/3.1.txt

@@ -139,6 +139,9 @@ Minor features
   ``'django.template.context_processors.request'`` in the
   ``'context_processors'`` option of :setting:`OPTIONS <TEMPLATES-OPTIONS>`.
 
+* Initially empty ``extra`` inlines can now be removed, in the same way as
+  dynamically created ones.
+
 * ``XRegExp`` is upgraded from version 2.0.0 to 3.2.0.
 
 * jQuery is upgraded from version 3.4.1 to 3.5.1.