Fix render-image.html for SVG

SVG images do not support resizing, so `srcset/src` attributes should be simplified

layouts/_default/_markup/render-image.html

@@ -15,6 +15,13 @@
   {{ end }}
   {{ with $resource }}
     <figure>
+      {{ if eq .MediaType.SubType "svg" }}
+        <img
+            class="my-0 rounded-md"
+            src="{{ .RelPermalink }}"
+            alt="{{ $altText }}"
+        />
+      {{ else }}
         <img
             class="my-0 rounded-md"
             srcset="
@@ -25,6 +32,7 @@
             src="{{ (.Resize "660x").RelPermalink }}"
             alt="{{ $altText }}"
         />
+      {{ end }}
       {{ with $caption }}<figcaption>{{ . | markdownify }}</figcaption>{{ end }}
     </figure>
   {{ else }}