fix(theme): Make fixes to the 3d model viewer page

src/layouts/3d-models/single.html

@@ -14,7 +14,7 @@ <h1>{{ .Title }}</h1>
             {{ range $_, $model := .Params.model3d }}
                 <div class="model3d">
                     <h2>{{ $model.title }}</h2>
-                    {{ if isset $model "description" }}
+                    {{ if and (isset $model "description") (gt (len $model.description) 0) }}
                         <p>{{ $model.description }}</p>
                     {{ end }}
                     {{ range $_, $file := $model.files }}
@@ -29,7 +29,7 @@ <h2>{{ $model.title }}</h2>
                               ar-status="not-presenting"></model-viewer>
                         </div>
                     {{ end }}
-                    {{ if isset $model "homepage"}}
+                    {{ if and (isset $model "homepage") (gt (len $model.homepage) 0) }}
                         <p>Homepage: <a href="{{ $model.homepage }}">{{ $model.homepage }}</a></p>
                     {{ end }}
                     {{ if isset $model "license" }}

test/content/3d-models.en.md

@@ -3,7 +3,8 @@ title: 3D Models
 type: 3d-models
 model3d:
   - title: Test viewing of Neil Armstrong
-    description: This is a test with a 3d model of Neil Armstrongn
+    description: This is a test with a 3d model of Neil Armstrong
+    homepage: https://example.org/
     files:
       - name: NeilArmstrong.3mf
         modelFile: https://via.placeholder.com/150

test/content/3d-models.md

@@ -4,6 +4,7 @@ type: 3d-models
 model3d:
   - title: Test visning av Neil Armstrong
     description: Detta är ett test med en 3d-modell av Neil Armstrong
+    homepage: https://example.org/
     files:
       - name: NeilArmstrong.3mf
         modelFile: https://via.placeholder.com/150