Fix typo

Author: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://postgr.es/m/0CF087FC-BEAD-4010-8BB9-3CDD74DC9060@yesql.se

Author: mhagander

doc/src/sgml/ref/create_table.sgml

@@ -958,7 +958,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
 
      <para>
       When placed on a partitioned table, <literal>PRIMARY KEY</literal>
-      constraints share the restrictions previously decribed
+      constraints share the restrictions previously described
       for <literal>UNIQUE</literal> constraints.
      </para>