Link how-tos and explanations to Tutorials

Description

There is some anecdotal evidence that new starters are struggling with the Guideboook because they are try to follow the Explanations and Reference sections of the Guidebook rather using the Tutorial sections.

This can be confusing as there is a lot of information in those other sections.

We should add 'TL;DR' links to ensure new starters follow the tutorial first and then come back for a more detailed guide.