content.txt

Some Text with the product (product: test)

index.php

<?php 

// site/plugins/products/index.php

Kirby::plugin('dantz/products', [
    'tags' => [
        'product' => [
            'html' => function ($tag) {

                if ($product = page('products/' . $tag->value())) {
                    return snippet('product', ['product' => $product], true);
                }

                return '';
            }
        ]
    ]  
]);

products.php

<!-- site/snippets/product.php -->
<article class="product">
  <!-- image and stuff -->
  <?= $product->title() ?>
</article>