In CREATE FOREIGN TABLE syntax synopsis, fix partitioning stuff.

Foreign tables can be partitioned, but previous documentation commits
left the syntax synopsis both incomplete and incorrect.

Justin Pryzby and Amit Langote

Discussion: http://postgr.es/m/20220521130922.GX19626@telsasoft.com

doc/src/sgml/ref/create_foreign_table.sgml

@@ -35,7 +35,8 @@ CREATE FOREIGN TABLE [ IF NOT EXISTS ] <replaceable class="parameter">table_name
   { <replaceable class="parameter">column_name</replaceable> [ WITH OPTIONS ] [ <replaceable class="parameter">column_constraint</replaceable> [ ... ] ]
     | <replaceable>table_constraint</replaceable> }
     [, ... ]
-) ] <replaceable class="parameter">partition_bound_spec</replaceable>
+) ]
+{ FOR VALUES <replaceable class="parameter">partition_bound_spec</replaceable> | DEFAULT }
   SERVER <replaceable class="parameter">server_name</replaceable>
 [ OPTIONS ( <replaceable class="parameter">option</replaceable> '<replaceable class="parameter">value</replaceable>' [, ... ] ) ]
 
@@ -52,6 +53,13 @@ CREATE FOREIGN TABLE [ IF NOT EXISTS ] <replaceable class="parameter">table_name
 
 [ CONSTRAINT <replaceable class="parameter">constraint_name</replaceable> ]
 CHECK ( <replaceable class="parameter">expression</replaceable> ) [ NO INHERIT ]
+
+<phrase>and <replaceable class="parameter">partition_bound_spec</replaceable> is:</phrase>
+
+IN ( <replaceable class="parameter">partition_bound_expr</replaceable> [, ...] ) |
+FROM ( { <replaceable class="parameter">partition_bound_expr</replaceable> | MINVALUE | MAXVALUE } [, ...] )
+  TO ( { <replaceable class="parameter">partition_bound_expr</replaceable> | MINVALUE | MAXVALUE } [, ...] ) |
+WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REMAINDER <replaceable class="parameter">numeric_literal</replaceable> )
 </synopsis>
  </refsynopsisdiv>