update: improving object expression examples (#4339)

* update: improving object expression examples

* small change in usecases

* implementing review comments

* some minor formatting

* removing bulletpoint about limited subclassing

* minor changes

* fixing link

* article fix

* implementing comments from Sarah

* implementing final review comments

* turning note to regular text

* last changes

* fixing typo

* fixing one last code comment before publishing

Author: daniCsorbaJB