removed is-narrow because useless in this case

docs/documentation/columns/options.html

@@ -44,10 +44,9 @@ breadcrumb:
 
 {% capture columns_mobile_centered %}
 <div class="columns is-mobile is-centered">
-  <div class="column is-half is-narrow">
+  <div class="column is-half">
     <p class="bd-notification is-primary">
       <code class="html">is-half</code><br>
-      <code class="html">is-narrow</code>
     </p>
   </div>
 </div>
@@ -135,10 +134,9 @@ breadcrumb:
 </div>
 
 <div class="columns is-mobile is-centered">
-  <div class="column is-half is-narrow">
+  <div class="column is-half">
     <p class="bd-notification is-primary">
       <code class="html">is-half</code><br>
-      <code class="html">is-narrow</code>
     </p>
   </div>
 </div>