Add RECURSIVE to documentation index

Author: Daniel Vérité <daniel@manitou-mail.org>
Reviewed-by: Fabien COELHO <coelho@cri.ensmp.fr>
Discussion: https://postgr.es/m/76d905d7-7eb7-4574-b6ec-a0ca3a1523c0@manitou-mail.org

doc/src/sgml/queries.sgml

@@ -1981,6 +1981,10 @@ GROUP BY region, product;
   </para>
 
   <para>
+   <indexterm>
+    <primary>RECURSIVE</primary>
+    <secondary>in common table expressions</secondary>
+   </indexterm>
    The optional <literal>RECURSIVE</literal> modifier changes <literal>WITH</literal>
    from a mere syntactic convenience into a feature that accomplishes
    things not otherwise possible in standard SQL.  Using

doc/src/sgml/ref/create_view.sgml

@@ -82,7 +82,12 @@ CREATE [ OR REPLACE ] [ TEMP | TEMPORARY ] [ RECURSIVE ] VIEW <replaceable class
    </varlistentry>
 
    <varlistentry>
-    <term><literal>RECURSIVE</literal></term>
+    <term><literal>RECURSIVE</literal>
+      <indexterm zone="sql-createview">
+       <primary>RECURSIVE</primary>
+       <secondary>in views</secondary>
+      </indexterm>
+    </term>
     <listitem>
      <para>
       Creates a recursive view.  The syntax