test(manual): fix description (webpack-contrib#267)

Author: TheAlexLichter

test/manual/index.html

@@ -36,11 +36,11 @@
   </div>
   <div class="test preloaded-css1">
     <p>Preloaded CSS: Must be green.</p>
-    <p><button class="preloaded-button1">Pressing this button</button> displays an alert but has no styling effect.</p>
+    <p><button class="preloaded-button1">Pressing this button</button> displays an alert and should turn red.</p>
   </div>
   <div class="test preloaded-css2">
     <p>Preloaded inlined CSS: Must be green.</p>
-    <p><button class="preloaded-button2">Pressing this button</button> displays an alert but has no styling effect.</p>
+    <p><button class="preloaded-button2">Pressing this button</button> displays an alert and should turn red.</p>
   </div>
   <div class="errors"></div>
   <script async defer src="/dist/main.js"></script>