blog: add wrap-up paragraph connecting typst-gather to the headline features

Author: gordonwoodhull

docs/blog/posts/2026-02-xx-typst-books-etc/index.qmd

@@ -80,3 +80,5 @@ Quarto 1.9 automatically stages Typst packages — from your extensions, from Qu
 To make this work, extension authors use the new [`typst-gather`](/docs/advanced/typst/typst-gather.qmd) tool, which scans their `.typ` files for `@preview` imports and downloads the packages into the extension directory. Authors run `quarto call typst-gather` and commit the results — users of the extension don't need to do anything.
 
 This means [Custom Typst Formats](/docs/output-formats/typst-custom.qmd#custom-formats) can depend on Typst packages without copying and pasting Typst code, making them simpler and easier to maintain.
+
+Both Typst books and article layout are built on `typst-gather` — orange-book depends on the Typst [orange-book](https://typst.app/universe/package/orange-book) package, and article layout depends on [Marginalia](https://typst.app/universe/package/marginalia/). As the Typst package ecosystem grows, we're excited to see what the community builds with these tools.