rm outdated note about lack of .col-{xs,sm}-offset-0; fixes #12439

docs/css.html

@@ -355,7 +355,7 @@ lead: "Global CSS settings, fundamental HTML elements styled and enhanced with e
   <div class="col-xs-6 col-sm-3">.col-xs-6 .col-sm-3</div>
 </div>
 {% endhighlight %}
-  <p>In addition to column clearing at responsive breakpoints, you may need to <strong>reset offsets, pushes, or pulls</strong>. Those resets are available for medium and large grid tiers only, since they start only at the (second) small grid tier. See this in action in <a href="../examples/grid/">the grid example</a>.</p>
+  <p>In addition to column clearing at responsive breakpoints, you may need to <strong>reset offsets, pushes, or pulls</strong>. See this in action in <a href="../examples/grid/">the grid example</a>.</p>
 {% highlight html %}
 <div class="row">
   <div class="col-sm-5 col-md-6">.col-sm-5 .col-md-6</div>