Revise list of available documentation versions

For older releases, the previous rendering wasn't quite right.
Implement a custom layout for the supported versions list

This commit does NOT remove the shortcode named {{< versions-other >}}
because it is still used in some localizations.

content/en/docs/home/supported-doc-versions.md

@@ -1,30 +1,12 @@
 ---
-title: Supported Versions of the Kubernetes Documentation
-content_type: concept
+title: Available Documentation Versions
+content_type: custom
+layout: supported-versions
 card:
   name: about
   weight: 10
-  title: Supported Versions of the Documentation
+  title: Available Documentation Versions
 ---
 
-<!-- overview -->
-
 This website contains documentation for the current version of Kubernetes
 and the four previous versions of Kubernetes.
-
-
-
-<!-- body -->
-
-## Current version
-
-The current version is
-[{{< param "version" >}}](/).
-
-## Previous versions
-
-{{< versions-other >}}
-
-
-
-

i18n/en.toml

@@ -54,6 +54,15 @@ other = "I AM..."
 [docs_label_users]
 other = "Users"
 
+[docs_version_current]
+other = "(this documentation)"
+
+[docs_version_latest_heading]
+other = "Latest version"
+
+[docs_version_other_heading]
+other = "Older versions"
+
 [examples_heading]
 other = "Examples"
 

layouts/docs/supported-versions.html

@@ -0,0 +1,39 @@
+{{ define "main" }}
+    <div class="td-content">
+    {{ partial "docs/content-page" (dict "ctx" . "page" .) }}
+    {{ $versions := .Page.Param "versions" }}
+    {{ $thisPageRelUri := .Page.RelPermalink }}
+    {{ $thisVersionArray := split (.Page.Param "version") "." }}
+    {{ $.Scratch.Set "version-class" (slice "placeholder") }}
+    {{/* "placeholder" is also used later to check whether we opened the <ul> */}}
+    {{ range $index, $version := $versions }}
+    {{ $.Scratch.Set "version-class" (slice "") }}
+    {{ $versionArray := split .version "." }}
+
+    {{ if eq $index 0 }}
+    <h2 id="version-latest">{{ T "docs_version_latest_heading" }}</h2>
+    <ul>
+    {{ $.Scratch.Set "version-class" ($.Scratch.Get "version-class" | append "version-latest" ) }}
+    {{ end }}
+    {{ if eq $index 1 }}
+    </ul>
+    <h2 id="versions-older">{{ T "docs_version_other_heading" }}</h2>
+    <ul>
+    {{ end }}
+
+    {{ if eq .version ( delimit $thisVersionArray "." ) }}
+    {{ $.Scratch.Set "version-class" ($.Scratch.Get "version-class" | append "version-current" ) }}
+    {{ end }}
+
+    <li class="{{ delimit ( $.Scratch.Get "version-class") " " }}">
+        <a href="{{ .url }}{{ $thisPageRelUri }}">{{ .version }}</a>
+        {{ if eq .version ( delimit $thisVersionArray "." ) }}
+        {{ T "docs_version_current" }}
+        {{ end }}
+    </li>
+    {{ end }}
+    {{ if ne (index ($.Scratch.Get "version-class") 0) "placeholder" }}
+    </ul>
+    {{ end }}
+
+{{ end }}