IMPROVE: reduce field placeholder setting textarea width

assets/javascripts/discourse/templates/components/wizard-custom-field.hbs

@@ -120,6 +120,7 @@
     <div class="setting-value">
       {{textarea
         name="field_placeholder"
+        class="medium"
         value=field.placeholder}}
     </div>
   </div>

assets/stylesheets/common/wizard-admin.scss

@@ -256,6 +256,10 @@
         width: 100%;
         box-sizing: border-box;
         margin-bottom: 0;
+
+        &.medium {
+          width: 40%;
+        }
       }
 
       input[type="number"] {