Enhancement: Custom Group By definitions

[michaeltlombardi]

Is your feature request related to a problem? Please describe.

My content is organized by several sub-projects (in my case, different web-books, with supplementary materials). Right now, I have defined several different page folders (via frontMatter.content.pageFolders) to have some control over what I see. Within those folders, I'm limited to grouping by year and draft/published status.

Describe the solution you'd like

I would like to be able to define custom grouping options with a new frontMatter.content.grouping key, similar to how I can define custom sorting options with frontMatter.content.sorting. For example, I might define a grouping by kind (core vs supplement).

Non-required but also very useful in my opinion would be multi-property groupings, so group first by kind and then by book_name, for example. So then in the supplements group the pages belonging to the Foo book would be grouped together, then the pages belonging to Bar.

Describe alternatives you've considered

The SSG-aware configuration discussed in #254 could also possibly resolve this problem, but seems more complex (and separately useful).

Additional context

N/A

[estruyf]

This would indeed be a great feature to add to Front Matter. Thanks, @michaeltlombardi, for the suggestion. You're on fire with your feedback!

[michaeltlombardi]

💜 I've spent the better part of a week excitedly configuring things with an eye towards the DevX/UX of my theme users, which has certainly helped me find use cases!