Render island shortcode as fallback image in Markdown output (#2762)

qdrant-landing/layouts/shortcodes/island.markdown.md

@@ -0,0 +1,20 @@
+{{- /*
+  island (Markdown output variant).
+
+  The HTML variant (themes/.../layouts/shortcodes/island.html) emits the full
+  interactive island: the loader picks up the `.island` figure, imports the
+  module, and swaps the fallback for the live widget. None of that machinery
+  works in the plain-text Markdown output (index.md, consumed by LLMs and the
+  docs mirror) — it would just dump the `<figure class="island">…` shell with
+  dead data-island-src/css asset URLs.
+
+  So in Markdown output an island degrades to what its fallback already is: a
+  regular Markdown image, followed by the shared `title` as an italic caption.
+*/ -}}
+{{- $fallback := trim (.Inner | default "") "\n " -}}
+{{- $title := trim (.Get "title" | default "") " " -}}
+{{ $fallback }}
+{{- with $title }}
+
+*{{ . }}*
+{{ end -}}