Dynamic related articles in PHP without a database

The "related articles" section at the bottom of a blog post is exactly the kind of thing you hardcode at first — two links picked by hand — and then forget to maintain. The result: stale suggestions pointing to unrelated articles, or worse, articles that no longer exist. On this blog, all content is described in a single posts.json file, with each article's slug, category, and tags. That's enough to automatically calculate relevant suggestions without a database. The problem with hardcoded links