fix typo in base css docs

docs/base-css.html

@@ -105,7 +105,7 @@
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       <h3>Typographic scale</h3>
-      <p>The entire typographic grid is based on two Less variables in our preboot.less file: <code>@baseFontSize</code> and <code>@baseLineHeight</code>. The first is the base font-size used throughout and the second is the base line-height.</p>
+      <p>The entire typographic grid is based on two Less variables in our variables.less file: <code>@baseFontSize</code> and <code>@baseLineHeight</code>. The first is the base font-size used throughout and the second is the base line-height.</p>
       <p>We use those variables, and some math, to create the margins, paddings, and line-heights of all our type and more.</p>
     </div>
     <div class="span4">

docs/templates/pages/base-css.mustache

@@ -29,7 +29,7 @@
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       <h3>{{_i}}Typographic scale{{/i}}</h3>
-      <p>{{_i}}The entire typographic grid is based on two Less variables in our preboot.less file: <code>@baseFontSize</code> and <code>@baseLineHeight</code>. The first is the base font-size used throughout and the second is the base line-height.{{/i}}</p>
+      <p>{{_i}}The entire typographic grid is based on two Less variables in our variables.less file: <code>@baseFontSize</code> and <code>@baseLineHeight</code>. The first is the base font-size used throughout and the second is the base line-height.{{/i}}</p>
       <p>{{_i}}We use those variables, and some math, to create the margins, paddings, and line-heights of all our type and more.{{/i}}</p>
     </div>
     <div class="span4">