Doc: Update struct Trigger definition.

Etsuro Fujita · Etsuro Fujita · commit ea4a066e5f15 · 2022-09-02T16:45:01.000+09:00
Commit 487e986 added a new field to struct Trigger, but failed to update the documentation to match; backpatch to v13 where that came in. Reviewed by Richard Guo. Discussion: https://postgr.es/m/CAPmGK17NY92CyxJ%2BBG7A3JZurmng4jfRfzPiBTtNupGMF0xW1g%40mail.gmail.com
diff --git a/doc/src/sgml/trigger.sgml b/doc/src/sgml/trigger.sgml
@@ -721,6 +721,7 @@ typedef struct Trigger
     int16       tgtype;
     char        tgenabled;
     bool        tgisinternal;
+    bool        tgisclone;
     Oid         tgconstrrelid;
     Oid         tgconstrindid;
     Oid         tgconstraint;
