make the size of containers on default pages bigger.

Author: Erik2609

themes/bigspring-light/layouts/_default/single.html

@@ -28,7 +28,7 @@ <h2 class="mb-4" style="color: #005aa7;">{{ .Title }}</h2>
 <section class="section">
   <div class="container">
     <div class="row">
-      <div class="col-lg-10 mx-auto">
+      <div class="col-lg-12 mx-auto">
         <div class="content">{{ .Content }}</div>
       </div>
     </div>