Landing: Added extra doc to exampleSite

Author: lamATnginx

exampleSite/content/test-product/_index.md

@@ -4,10 +4,13 @@ title: Test pages
 weight: 100
 hasCustomContent: true
 ---
+<!-- <card-layout> - Available params: title (required: string)-->
 {{< card-layout >}}
+  <!-- <card-section> - Available params: title (required: string), showAsCards (optional: boolean, default false) -->
   <!-- If there is no "title" for <card-section>, it is implied it is the main content section and not a new content section -->
   {{< card-section >}}
     {{< card title="Call Out usages" >}}
+      <!-- <card> - Available params: title (required: string), titleUrl (optional: string, relative path or absolute URL (e.g. https://google.com)) -->
       Examples for call-out shortcode
     {{</ card >}}
     {{< card title="Code Block usages" >}}

layouts/shortcodes/card.html

@@ -10,7 +10,9 @@ <h2 class="card-title"><a href="{{- .Get "titleUrl" -}}">{{- .Get "title" -}}</a
       {{- else -}}
         <h2 class="card-title">{{- .Get "title" -}}</h2>
       {{- end -}}
-    {{ end }}
+    {{- else -}}
+      {{ errorf "Missing param 'title'" }}
+    {{- end -}}
     <p>{{- .Inner -}}</p>
   </div>
   <div class="col-md-5 card" data-mf="false">
@@ -19,7 +21,11 @@ <h3 class="card-title" style="display: flex; align-items: center; gap: 5px;">
         {{- if .Get "icon" -}}
           <img class="card-img-top" src="{{ .Site.BaseURL }}/images/icons/{{ .Get "icon" }}.png"/>
         {{- end -}}
-        <a href="{{- .Get "titleUrl" -}}">{{- .Get "title" -}}</a>
+        {{- if and (.Get "title") (.Get "titleUrl") -}}
+          <a href="{{- .Get "titleUrl" -}}">{{- .Get "title" -}}</a>
+        {{- else -}}
+          {{ errorf "Missing either params 'titleUrl' or 'title'" }}
+        {{- end -}}
       </h3>
       <p>{{- .Inner -}}</p>
     </div>