docs: update with notes about validity for zips (#2963)

* docs: update with notes about validity for zips

* update with locale

doc/default/address.md

@@ -17,10 +17,13 @@ Faker::Address.mail_box #=> "PO Box 123"
 
 Faker::Address.community #=> "University Crossing"
 
+#note: #zip_code will return a random string in zipcode format; may or may not be a valid zip for locale
 Faker::Address.zip_code #=> "58517" or "23285-4905"
 
+#note: #zip will return a random string in zipcode format; may or may not be a valid zip for locale
 Faker::Address.zip #=> "58517" or "66259-8212"
 
+#note: #postcode will return a random string in postcode format; may or may not be a valid zip for locale
 Faker::Address.postcode #=> "76032-4907" or "58517"
 
 Faker::Address.time_zone #=> "Asia/Yakutsk"

lib/faker/default/address.rb

@@ -119,8 +119,8 @@ def zip_code(state_abbreviation: '')
           return numerify(letterified_string, leading_zero: true)
         end
 
-        # provide a zip code that is valid for the state provided
-        # see http://www.fincen.gov/forms/files/us_state_territory_zip_codes.pdf
+        # provide a zip code that may be valid for the state provided
+        # note: zip code may appear in the correct format for the state provided but may not be an actual state zip.
         bothify(fetch("address.postcode_by_state.#{state_abbreviation}"))
       end