Feature request: Support for bidirectional links / backlinks (like Zola)

[theowenyoung]

Hi 👋

First of all, thanks for the great work on Zine — I really like how elegant and fast it is!

I’d like to request a feature for bidirectional links (or backlinks), similar to what Zola supports.

In Zola, each page or section has access to a list of pages that link to it via a backlinks array:

// All the pages/sections linking this page: their permalink and a title if there is one
backlinks: Array<{permalink: String, title: String?}>;

This is super helpful for building wiki-like sites or digital gardens, where showing “linked references” enhances navigation and context.

It would be great if Zine could automatically collect and expose backlinks in a similar way — either as a built-in variable accessible in templates, or as part of the page metadata.

Use cases:
• Showing “Referenced by” sections at the bottom of pages
• Easier navigation in knowledge-base-style blogs
• Internal note-linking systems (digital garden setups)

Would love to hear if this feature might fit into Zine’s roadmap, or if you’d accept a PR for it!

Thanks 🙏