Add reusable layout partials for easier page creation

- Create content-card-section.html partial for card-based content
- Create step-by-step-section.html partial for process steps
- Create contact-section.html partial for contact information
- Create main-content-section.html general purpose partial that combines all elements
- Add simplified examples using the new partials (acheter-credit-simple and commande-sim-simple)
- These partials follow the existing site theme and make creating new pages much faster

layouts/partials/content-card-section.html

@@ -0,0 +1,31 @@
+{{ $title := .title }}
+{{ $subtitle := .subtitle }}
+{{ $cards := .cards }}
+
+<div class="container">
+  <div class="row">
+    <div class="col-12">
+      <div class="card mb-4">
+        <div class="card-body">
+          <h2 class="card-title">{{ $title }}</h2>
+          {{ if $subtitle }}<p>{{ $subtitle }}</p>{{ end }}
+          
+          {{ if $cards }}
+          <div class="row mt-4">
+            {{ range $cards }}
+            <div class="col-md-{{ div 12 (len $cards) }}">
+              <div class="card h-100">
+                <div class="card-body text-center">
+                  <h4>{{ .title }}</h4>
+                  <p>{{ .description }}</p>
+                </div>
+              </div>
+            </div>
+            {{ end }}
+          </div>
+          {{ end }}
+        </div>
+      </div>
+    </div>
+  </div>
+</div>