-TODO insert note about #t helper compared to I18n.t
-TODO insert note/reference about structuring translation keys
When you now render this view it will show an error message that tells you that the translations for the keys :hello_world and :hello_flash are missing.
+NOTE: Rails adds a +t+ (+translate+) helper method to your views so that you do not need to spell out +I18n.t+ all the time. Additionally this helper will catch missing translations and wrap the resulting error message into a <span class="translation_missing">.
So let's add the missing translations (i.e. do the "localization" part):