Simplify release list on downloads page (en)

Stop distinguishing between "current", "previous", ... releases,
simply list them under "stable releases". This allows iterating
over the corresponding site variable (an array).

Author: stomar

en/downloads/index.md

@@ -34,22 +34,14 @@ See the [Installation][installation] page for details on building
 Ruby from source. If you have an issue compiling Ruby, consider using
 one of the third party tools mentioned above. They may help you.
 
-* **Current stable:**
-  [Ruby {{ site.downloads.stable[0].version }}]({{ site.downloads.stable[0].url.gz }})<br>
-  sha256: {{ site.downloads.stable[0].sha256.gz }}
-
-* **Previous stable:**
-  [Ruby {{ site.downloads.stable[1].version }}]({{ site.downloads.stable[1].url.gz }})<br>
-  sha256: {{ site.downloads.stable[1].sha256.gz }}
-
-* **Old stable:**
-  [Ruby {{ site.downloads.stable[2].version }}]({{ site.downloads.stable[2].url.gz }})<br>
-  sha256: {{ site.downloads.stable[2].sha256.gz }}
+* **Stable releases:**{% for release in site.downloads.stable %}
+  * [Ruby {{ release.version }}]({{ release.url.gz }})<br>
+    sha256: {{ release.sha256.gz }}{% endfor %}
 
 {% if site.downloads.security_maintenance %}
-* **In security maintenance phase (will EOL soon!):**
-  [Ruby {{ site.downloads.security_maintenance[0].version }}]({{ site.downloads.security_maintenance[0].url.gz }})<br>
-  sha256: {{ site.downloads.security_maintenance[0].sha256.gz }}
+* **In security maintenance phase (will EOL soon!):**{% for release in site.downloads.security_maintenance %}
+  * [Ruby {{ release.version }}]({{ release.url.gz }})<br>
+    sha256: {{ release.sha256.gz }}{% endfor %}
 {% endif %}
 
 * **Snapshots:**