Add missing support to generate OSTree URLs in shortcode

The shortcode is missing the ability to create URLs to ostree images. This
is vital since the download page should be serving OSTree images!

Signed-off-by: Martyn Welch <martyn.welch@collabora.com>

content/download.md

@@ -22,9 +22,9 @@ release images presented below for evaluation.
 
   | Image | Optional Downloads |
   | ----- | ------------------ |
-  | [Intel 64-bit (amd64)]({{< image-url Stable amd64 minimal >}}) | [bmap file]({{< image-url Stable amd64 minimal bmap >}}) |
-  | [ARM 32-bit (armhf)]({{< image-url Stable armhf minimal >}}) | [bmap file]({{< image-url Stable armhf minimal bmap >}}) |
-  | [ARM 64-bit (arm64)]({{< image-url Stable arm64 minimal >}}) | [bmap file]({{< image-url Stable arm64 minimal bmap >}}) |
+  | [Intel 64-bit (amd64)]({{< image-url Stable amd64 minimal ostree >}}) | [bmap file]({{< image-url Stable amd64 minimal ostree bmap >}}) |
+  | [ARM 32-bit (armhf)]({{< image-url Stable armhf minimal ostree >}}) | [bmap file]({{< image-url Stable armhf minimal ostree bmap >}}) |
+  | [ARM 64-bit (arm64)]({{< image-url Stable arm64 minimal ostree >}}) | [bmap file]({{< image-url Stable arm64 minimal ostree bmap >}}) |
 
 - **Target**: A more featureful image, utilizing
   [OSTree]({{< ref "guides/ostree.md" >}}) for updates, providing an example
@@ -33,8 +33,8 @@ release images presented below for evaluation.
 
   | Image | Optional Downloads |
   | ----- | ------------------ |
-  | [Intel 64-bit (amd64)]({{< image-url Stable amd64 target >}}) | [bmap file]({{< image-url Stable amd64 target bmap >}}) |
-  | [ARM 32-bit (armhf)]({{< image-url Stable armhf target >}}) | [bmap file]({{< image-url Stable armhf target bmap >}}) |
+  | [Intel 64-bit (amd64)]({{< image-url Stable amd64 target ostree >}}) | [bmap file]({{< image-url Stable amd64 target ostree bmap >}}) |
+  | [ARM 32-bit (armhf)]({{< image-url Stable armhf target ostree >}}) | [bmap file]({{< image-url Stable armhf target ostree bmap >}}) |
 
   {{% notice note %}}
   No open graphical stack is available for the current stable release on the

layouts/shortcodes/image-url.html

@@ -3,9 +3,13 @@
 {{ $release := (.Get 0) }}
 {{ $arch := (.Get 1) }}
 {{ $type := (.Get 2) }}
+{{ $variant := (.Get 3) }}
+{{ $extra := (.Get 4) }}
 
 {{ $scratch := newScratch }}
 
+{{ $scratch.Set "variant" "" }}
+
 {{ if eq $type "sdk" }}
   {{ $scratch.Set "extension" ".vdi.gz" }}
   {{ $scratch.Set "firmware" $type }}
@@ -16,16 +20,20 @@
   {{ else }}
     {{ $scratch.Set "firmware" "uboot" }}
   {{ end }}
+  {{ if eq $variant "ostree" }}
+    {{ $scratch.Set "variant" "_ostree" }}
   {{ end }}
-{{ if eq (.Get 3) "bmap" }}
-  {{ $scratch.Set "extension" ".img.bmap" }}
 {{ end }}
 
+{{ if eq $extra "bmap" }}
+  {{ $scratch.Set "extension" ".img.bmap" }}
+{{ end }}
 
 {{ $extension := $scratch.Get "extension" }}
 {{ $firmware := $scratch.Get "firmware" }}
+{{ $variant := $scratch.Get "variant" }}
 
 {{ $version := (index .Site.Data.releases $release).version }}
 {{ $revision := (index .Site.Data.releases $release).revision }}
 
-{{ $baseurl }}/{{ $version }}/{{ $version }}.{{ $revision }}/{{ $arch }}/{{ $type }}/apertis_{{ $version }}-{{ $type }}-{{ $arch }}-{{ $firmware }}_{{ $version}}.{{ $revision }}{{ $extension }}
+{{ $baseurl }}/{{ $version }}/{{ $version }}.{{ $revision }}/{{ $arch }}/{{ $type }}/apertis{{ $variant }}_{{ $version }}-{{ $type }}-{{ $arch }}-{{ $firmware }}_{{ $version}}.{{ $revision }}{{ $extension }}