Allowing other extensions for app images.

layouts/_default/app.html

@@ -30,11 +30,11 @@
                     {{ .Content | markdownify }}
                 </div>
                 <div class="column col2">
-                    <img class="vertical-center fill-width" alt="{{ .Alt }}" src="/img/{{ .Image }}.png" loading="lazy"/>
+                    <img class="vertical-center fill-width" alt="{{ .Alt }}" src="/img/{{ .Image }}" loading="lazy"/>
                 </div>
             {{ else if eq .Type "image|text" }}
                 <div class="column col2">
-                    <img class="vertical-center fill-width" alt="{{ .Alt }}" src="/img/{{ .Image }}.png" loading="lazy"/>
+                    <img class="vertical-center fill-width" alt="{{ .Alt }}" src="/img/{{ .Image }}" loading="lazy"/>
                 </div>
                 <div class="column col2 text-left vertical-center">
                     {{ .Content | markdownify }}
@@ -42,7 +42,7 @@
             {{ else if eq .Type "text/image" }}
                 <div class="column text-center">
                     {{ .Content | markdownify }}
-                    <img src="/img/{{ .Image }}.png" alt="{{ .Alt }}" loading="lazy"/>
+                    <img src="/img/{{ .Image }}" alt="{{ .Alt }}" loading="lazy"/>
                 </div>
             {{ else if eq .Type "text" }}
                 <div class="column text-center">