Fix grammar.

Reported by Peter Geoghegan.

Author: robertmhaas

doc/src/sgml/release-9.5.sgml

@@ -221,9 +221,9 @@
 
       <listitem>
        <para>
-        Extend the infrastructure allow sorting to be performed by inlined,
-        non-<acronym>SQL</acronym>-callable comparison functions to cover
-        <command>CREATE INDEX</>, <command>REINDEX</>, and
+        Extend the infrastructure that allows sorting to be performed by
+        inlined, non-<acronym>SQL</acronym>-callable comparison functions to
+        cover <command>CREATE INDEX</>, <command>REINDEX</>, and
         <command>CLUSTER</> (Peter Geoghegan)
        </para>
       </listitem>