refactor: Drop alt text from decorative elements and drop divider separator role since it's not valid on list elements

Signed-off-by: Felicitas Pojtinger <felicitas@pojtinger.com>

Author: pojntfx

data/content.yaml

@@ -33,9 +33,7 @@ home:
       - title: 2026 Cloud Summit
         date: May 1, 2026
         url: https://cloudsummit.ca
-        image:
-          src: img/cloudsummit-2026.jpg
-          alt: 2026 Cloud Summit venue in Vancouver
+        image: img/cloudsummit-2026.jpg
 
 events:
   past:

layouts/_partials/section-home.html

@@ -191,12 +191,10 @@ <h3>{{ .title }}</h3>
               <div
                 class="pf-v6-c-card pf-m-compact"
                 style="
-                  background-image: url('{{ .image.src | relURL }}');
+                  background-image: url('{{ .image | relURL }}');
                   background-size: cover;
                   background-position: center;
                 "
-                role="img"
-                aria-label="{{ .image.alt }}"
               >
                 <div class="pf-v6-c-card__body pf-v6-l-flex pf-m-column pf-m-justify-content-flex-end pf-m-gap-sm" style="
                   background: linear-gradient(color-mix(in srgb, var(--pf-t--global--background--color--primary--default) 40%, transparent) 0%, color-mix(in srgb, var(--pf-t--global--background--color--primary--default) 80%, transparent) 50%, var(--pf-t--global--background--color--primary--default) 100%);

layouts/_partials/sidebar.html

@@ -5,7 +5,7 @@
         {{ $current := $.RelPermalink }}
         {{ range .Site.Data.links.sidebar }}
           {{ if .separator }}
-            <li class="pf-v6-c-divider" role="separator"></li>
+            <li class="pf-v6-c-divider" role="presentation"></li>
           {{ else if .url }}
             <li class="pf-v6-c-nav__item">
               <a