Update apphooks.rst (#6255)
Update apphooks.rst (#6255)

* Update apphooks.rst

You need to add *Application instance name* by hand to a page when you add an ``app_name`` #hopeitsavessomeoneelsethetrouble

* Changed as per czpython's suggestions

While still trying to convey that we're fixing the same problem than the previous paragraphs refers to (and that *Application instance name* only appears after setting ``app_name`` )

FinalAngel/django-cms,FinalAngel/django-cms,FinalAngel/django-cms,FinalAngel/django-cms