Add sculpin bundles section

README.md

@@ -31,6 +31,38 @@ It's not mandatory to follow this recommendation, but it does help make
 it easier on maintainers. They'll be able to click the "Merge" button
 and the changes will be deployed immediately.
 
+Bundles
+-------
+
+The Bundles list on the home page and the community page is rendered
+from `app/config/bundles.yml`.
+
+`scripts/fetch-bundles.php` discovers bundles on GitHub and refreshes
+their metadata from GitHub and Packagist:
+
+    GITHUB_TOKEN=... composer fetch-bundles
+
+A repository is discovered if it has the `sculpin-bundle` topic, or if
+its name contains both "sculpin" and "bundle". The token is optional,
+but without one the GitHub Search API allows only 10 requests per
+minute.
+
+The script never publishes anything on its own. New finds are written to
+the `discovered` list, which is not rendered; a maintainer moves the
+entries that belong on the site into `bundles`, and adds anything that
+should never be listed to `ignored`.
+
+To add a bundle by hand, add an entry to `bundles` with a `name`,
+`repository` and `description`, then run the script to fill in the rest.
+It refreshes `description`, `version`, `updated`, `stars`, `archived`
+and `abandoned` on every run, keeps both lists in alphabetical order, and
+leaves everything else alone.
+
+What gets rendered is decided in
+`source/_views/includes/bundles.html`, not by the file order: bundles
+marked abandoned on Packagist are skipped, and the rest are listed most
+recently updated first.
+
 Notes
 -----