gl-sprintf 'basic' example invalid in gitlab

The 'Basic' example in Readme and Examples of gl-sprintf results in untranslated strings in the slots, which (correctly) breaks pipelines in gitlab. It might be worth adding the start/end example first, as that's most common non-component usage example.

There are a few broken translations due to using the 'basic' syntax to split sentences, mostly double translations (example)

This is possibly just a case of "read the docs properly next time"; externalization docs mention this already, but you can never be too careful