Update all existing content to use YAML explainer component

The [YAML file UI component] allows authors to clearly break down YAML files for users. This should be retrofitted to all content authored prior the introduction of the component.

Start by locating the YAML file UI component and inventorying content authored before its introduction. Review each older content item to identify where the component should be used; done means all applicable existing content has been retrofitted and remains readable.

Written by the indexing model from the issue text.