Fix fallback to resource title for figure caption

We can just use the resource shortcode in content files

hugo.yaml

@@ -4,8 +4,6 @@ markup:
     lineNos: true
   goldmark:
     parser:
-      # don't put <p> around ![]() image in markdown (used to embed any resource now)
-      wrapStandAloneImageWithinParagraph: false
       attribute:
         block: true
         # this is enabled by default already

layouts/_markup/render-image.html

@@ -1,12 +0,0 @@
-{{/* TODO: should we use .PageInner */}}
-{{ partial "embed-resource.html" (.Page.Resources.Get .Destination) }}
-{{ with .Title }}
-    {{ errorf "%q" . }}
-{{ end }}
-{{ with .Attributes }}
-    {{/* FIXME: https://github.com/gohugoio/hugo/blob/master/tpl/tplimpl/embedded/templates/_markup/render-image.html */}}
-    {{ errorf "%q" . }}
-{{ end }}
-{{ with .Text }}
-    {{ errorf "%q" . }}
-{{ end }}

layouts/_partials/embed-resource.html

@@ -6,12 +6,14 @@
     <img src="{{ .Permalink }}" {{ with .Params.alt }}alt="{{ . }}"{{ end }} />
 {{ else if eq .ResourceType "video" }}
     <video controls preload="metadata">
-        {{/* FIXME
-        <source src="{{ .Permalink }}" {{ with .Params.alt }}alt="{{ . }}"{{ end }} />
-        */}}
+        {{ with .Params.alt }}
+            {{ warnf "video does not support alt text, '%s'" . }}
+        {{ end }}
+        <source src="{{ .Permalink }}" />
         {{ i18n "browser_no_video_support" }}
         <a href="{{ .Permalink }}" target="_blank" rel="noopener">
             {{ i18n "browser_no_video_support_link" }}
+        </a>
     </video>
 {{ else }}
     {{/* TODO: could consider implementing more types, listed at:

layouts/_partials/feature-figure.html

@@ -3,7 +3,7 @@
         <figure>
             {{ partial "embed-resource.html" . }}
             {{ with .Title }}
-                <figcaption>{{ . }}</figcaption>
+                <figcaption>{{ . | markdownify }}</figcaption>
             {{ end }}
         </figure>
     </div>

layouts/_shortcodes/figure.html

@@ -1,17 +1,17 @@
 <figure>
+    {{ $resource_title := "" }}
     {{ with .Get "src" }}
         {{ with $.Page.Resources.Get . }}
+            {{ $resource_title = .Title }}
             {{ partial "embed-resource.html" . }}
-            {{ with .Title }}
-                <figcaption>{{ . | markdownify }}</figcaption>
-            {{ end }}
         {{ else }}
             {{ errorf "resource %q not found" . }}
         {{ end }}
     {{ else }}
         {{ .Inner }}
-        {{ with .Get "caption" }}
-            <figcaption>{{ . | markdownify }}</figcaption>
-        {{ end }}
+    {{ end }}
+
+    {{ with or (.Get "caption") (.Get 0) $resource_title }}
+        <figcaption>{{ . | markdownify }}</figcaption>
     {{ end }}
 </figure>