Merge pull request #9703 from rffontenelle/patch-1

doc: fix grammar of possessive of plural noun

Author: tk0miya

doc/_templates/index.html

@@ -118,7 +118,7 @@ <h2>{%trans%}Contributor Guide{%endtrans%}</h2>
     this part of the documentation is for you.{%endtrans%}</p>
 
     <ul>
-      <li>{%trans path=pathto("internals/contributing")%}<a href="{{ path }}">Sphinx Contributors’s Guide</a></li>{%endtrans%}
+      <li>{%trans path=pathto("internals/contributing")%}<a href="{{ path }}">Sphinx Contributors’ Guide</a></li>{%endtrans%}
       <li>{%trans path=pathto("internals/authors")%}<a href="{{ path }}">Sphinx Authors</a></li>{%endtrans%}
     </ul>