Typo fix in index topic

specification/archSpec/base/index-elements.dita

@@ -42,7 +42,7 @@
             </dlentry>
         </dl>
         <p>How the index elements are combined, the location of <xmlelement>indexterm</xmlelement>
-            elements, and the hierarchy of the DITA maps all effect how the index elements are
+            elements, and the hierarchy of the DITA maps all affect how the index elements are
             processed and the resulting generated index entries.</p>
         <!--<draft-comment author="Joyce Lam" time="09 August 2019"><p>For clarity, I recommend writing this using an unordered list.</p><p>How the index elements are processed and the resulting generated index entries are effected by</p><ul><li>how the index elements are combined</li><li>the location of &lt;indexterm> elements, and</li><li>the hierarchy of the DITA maps.</li></ul></draft-comment>-->
     </conbody>