feat(isabelle-edits): Clarify theme structure and add SVG icon support

Improves theme organization by adopting a 7-in-1 SCSS structure.

Introduces support for SVG icons within templates, enhancing visual flexibility.

Adds a checkmark SVG asset.

falcon/templates/_partials/header.tpl

@@ -33,11 +33,24 @@
 {/block}
 
 {block name='header_top'}
+    {* Optional: Add USP bar at the top of the header
+    Uncomment the code below to enable it 
+    Use the uspanywhere module and hook to "displayHeaderTopUsps" *}
+
+    {*
+    <div class="header-cta d-none d-lg-block py-2 py-lg-3 bg-primary">
+        <div class="container">
+            <div class="row d-flex gap-20">
+                {hook h='displayHeaderTopUsps'}
+            </div>
+        </div> 
+    </div> 
+    *}
+
     <div class="js-header-top-wrapper">
         <div class="header-top js-header-top">
             <div class="header-top__content pb-md-0 py-2">
                 <div class="container">
-
                     <div class="row header-top__row">
 
                         <div class="col flex-grow-0 header-top__block header-top__block--menu-toggle d-block d-md-none">