Update styles and templates for improved checkout experience

- Adjusted CSS styles in custom.css and custom.scss for better layout and responsiveness, including changes to button sizes and margins.
- Updated the checkout button link in ps_shoppingcart.tpl to directly point to the order page.
- Changed text labels in cart-voucher.tpl for better localization.
- Modified continue shopping button text in cart.tpl to Polish.
- Enhanced index.tpl structure for better hook management and layout consistency.
- Added temporary image files in the checkout module for future use.

themes/charme/templates/checkout/cart.tpl

@@ -44,9 +44,7 @@
         </div>
 
         {block name='continue_shopping'}
-          <a class="label btn btn-primary" href="{$urls.pages.index}">
-            {l s='Continue shopping' d='Shop.Theme.Actions'}
-          </a>
+          <a class="label btn btn-primary" href="{$urls.pages.index}">Kontynuuj zakupy</a>
         {/block}
 
         <!-- shipping informations -->