feat: enable PDF output for pages

Assisted-by: Delta:zai-glm-5.3

README.md

@@ -50,6 +50,10 @@ target = "<category>/<page>.typ"
 
 Sidebar labels come from the page's `#metadata(...)` line, not from the config.
 
+Every page also renders a printable PDF twin (`pdf = true` in
+`calepin.toml`, selectable in the page's view picker). Add `pdf: false` to a
+page's `#metadata(...)` to skip its PDF, as `404.typ` does.
+
 ## Adding a category
 
 1. Create `site/<category>/` with an `index.typ`, using
@@ -69,8 +73,9 @@ sidebar.
 
 ## Deployment
 
-`just build` produces a fully static site in `public/`: HTML pages plus
+`just build` produces a fully static site in `public/`: HTML pages with
-`sitemap.xml`, `robots.txt`, and `llms.txt`. The Gitea Actions workflow in
+printable PDF twins, plus `sitemap.xml`, `robots.txt`, and `llms.txt`. The
+Gitea Actions workflow in
 `.gitea/workflows/build.yml` builds the site on every push with the same
 pinned toolchain and uploads `public/` as an artifact for deployment to any
 static host.

site/404.typ

@@ -1,4 +1,5 @@
 #set document(title: [Not found])
+#metadata((pdf: false)) <website-metadata>
 
 #title()
 

site/calepin.toml

@@ -2,7 +2,7 @@ title = "Yggdrasil"
 description = "Personal knowledge base."
 base-url = "https://yggdrasil.kb28.ch"
 theme = "themes/yggdrasil"
-pdf = false
+pdf = true
 minify = true
 search = "pagefind"
 logo = "assets/yggdrasil.svg"