Card: Fixed relative pathing

Author: lamATnginx

exampleSite/content/_index.md

@@ -7,10 +7,10 @@ description:
 Documentation for hugo theme
 {{<card-layout>}}
   {{<card-section showAsCards="true">}}
-    {{<card title="Test Product" titleUrl="/test-product/" icon="test-tubes"  isLanding="true">}}
+    {{<card title="Test Product" titleUrl="test-product/" icon="test-tubes"  isLanding="true">}}
       See explanations and usages of shortcodes
     {{</card >}}
-    {{<card title="NGINX Plus" titleUrl="/nginx/" brandIcon="NGINX-Plus-product-icon-RGB"  isLanding="true">}}
+    {{<card title="NGINX Plus" titleUrl="nginx/" brandIcon="NGINX-Plus-product-icon-RGB"  isLanding="true">}}
       See a live example of theme components
     {{</card >}}
   {{</card-section>}}

exampleSite/content/test-product/_index.md

@@ -54,7 +54,7 @@ This is a compilation of all our shortcodes to show how they look, function, res
 
 {{<card-layout >}}
   {{<card-section title="NGINX" showAsCards="true" >}}
-    {{<card title="NGINX Plus" titleUrl="/nginx/" brandIcon="NGINX-Plus-product-icon-RGB" >}}
+    {{<card title="NGINX Plus" titleUrl="nginx/" brandIcon="NGINX-Plus-product-icon-RGB" >}}
       Installing NGINX
     {{</card >}}
   {{</card-section >}}

layouts/shortcodes/card.html

@@ -32,9 +32,16 @@
   {{ $dataGrid = "half"}}
 {{ end }}
 
+{{- /* Build the url */ -}}
+{{ if eq (substr $titleUrl 0 1) "/" }}
+  {{ $suggestedUrlFix := substr $titleUrl 1 }} 
+  {{ errorf "Please do not start the param 'titleUrl' with a forward slash. Got: '%s', use '%s' instead." $titleUrl $suggestedUrlFix }}
+{{ end }}
+{{ $url := printf "%s%s" .Page.Permalink $titleUrl }}
+
 {{- /* Validate that the parent is card-section and under 3 cards */ -}}
 {{- if (eq .Parent.Name "card-section") -}}
-<a href="{{- $titleUrl -}}" alt="{{- $title -}}" class="card{{ if eq $isFeatured "true" }} featured-card{{ end }}" data-grid="{{ $dataGrid }}" data-testid="{{ if eq $isFeatured "true" }}card__featured-card{{else}}card{{ end }}">
+<a href="{{- $url -}}" alt="{{- $title -}}" class="card{{ if eq $isFeatured "true" }} featured-card{{ end }}" data-grid="{{ $dataGrid }}" data-testid="{{ if eq $isFeatured "true" }}card__featured-card{{else}}card{{ end }}">
   <div class="card-container">
     {{- if $title -}}
       <div class="card-header">