Groups the suggestions about style together, so it's clear which suggestions are functional and which are not. Add links to the specific community style guide rules.

At this point in the track it's fine to use ANYTHING, but the notion that "class" is somehow more correct than module is off-putting.

A class should only be used if its functionality requires instantation. Utility functions and the sorts should either be on a named constant which is an Object, or a module so it can be included/extended and shared in other modules and classes.

The point of this exercise is to prepare a student for the track, not force one usage over another.

String interpolation is simpler, but template strings are much more maintainable when used with named arguments as it can be subtituted easily for internationalisation and/or extended.

This adds all the variations as reasonable so mentors no longer penalise students for using it.

I don't think this is still part of the actual implementation and thus does not need to be part of the mentor notes.

`format` is being used in the example, so `sprintf` is the alternative to that