Adding white-bg to horizontal link card

Author: msquance-stem

app/components/cms/horizontal_link_card_component.rb

@@ -11,7 +11,7 @@ def initialize(title:, link_url:, card_content:, theme:)
   end
 
   def wrapper_classes
-    classes = ["cms-horizontal-link-card"]
+    classes = ["cms-horizontal-link-card white-bg"]
     if @theme
       classes << cms_color_theme_class(@theme, "left")
       classes << "#{@theme}-theme"