Fix typo in CREATE PUBLICATION reference page

While at it, simplify wording a bit.

Author: Takamichi Osumi <osumi.takamichi@fujitsu.com>
Reviewed-by: Peter Smith <smithpb2250@gmail.com>
Discussion: https://postgr.es/m/TYCPR01MB8373F93F5D094A2BE648990DED259@TYCPR01MB8373.jpnprd01.prod.outlook.com

doc/src/sgml/ref/create_publication.sgml

@@ -184,8 +184,8 @@ CREATE PUBLICATION <replaceable class="parameter">name</replaceable>
 
   <para>
    For an <command>INSERT ... ON CONFLICT</command> command, the publication will
-   publish the operation that actually results from the command.  So depending
-   of the outcome, it may be published as either <command>INSERT</command> or
+   publish the operation that results from the command.  Depending
+   on the outcome, it may be published as either <command>INSERT</command> or
    <command>UPDATE</command>, or it may not be published at all.
   </para>