fixes typo on BEA data page (closes #356)

datausa/html/about/datasets.html

@@ -60,7 +60,7 @@ <h2>Description</h2>
         <h2>Where is it used?</h2>
         <p>The BEA I/O tables are used on the industry pages showing the input and output industries for the specified industry profile page.</p>
         <h2>Caveats</h2>
-        <p>The BEA I/O tables use a modified version of the North American Industry Classification (NAICS) meaning that certain industtry pages do not have a corresponding BEA I/O table industry and are thus swapped for the closest match.</p>
+        <p>The BEA I/O tables use a modified version of the North American Industry Classification (NAICS) meaning that certain industry pages do not have a corresponding BEA I/O table industry and are thus swapped for the closest match.</p>
       </div>
       <div class="dataset-tab" data-tab="4">
         <h2>Description</h2>