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/modules/ps_shoppingcart/ps_shoppingcart.tpl

@@ -142,7 +142,7 @@
             </div>
             <div class="cart-action">
               <div class="text-center">
-                <a href="{if Module::isEnabled('an_theme') and Module::getInstanceByName('an_theme')->getParam('shoppingCart_cartAction') == 'checkout'}{$urls.pages.order}{else}{$cart_url}{/if}" class="btn btn-primary">{l s='Proceed to checkout' d='Shop.Theme.Actions'}</a>
+                <a href="{$urls.pages.order}" class="btn btn-primary">{l s='Proceed to checkout' d='Shop.Theme.Actions'}</a>
               </div>
             </div>
           </div>