docs: Nonfunctional Example code in "/objects/Dropdown"

[Messier1071]

** Where? **

in this example, item.text is nil and item is a string saying "value changed"

** Possible solution **
updating the example to display the last field

aDropdown:onChange(function(self,Event, item)
  basalt.debug(Event)
  basalt.debug("Selected item: ".. item.text)
  
end)

** Others **
thank you for making such a library

** Checklist **
[X] I am looking at the latest version of the docs.
https://basalt.madefor.cc/#/objects/Dropdown