doc: make ref/*.sgml file header comment layout consistent

doc/src/sgml/ref/checkpoint.sgml

-<!-- doc/src/sgml/ref/checkpoint.sgml -->
+<!--
+doc/src/sgml/ref/checkpoint.sgml
+PostgreSQL documentation
+-->
 
 <refentry id="sql-checkpoint">
  <indexterm zone="sql-checkpoint">

doc/src/sgml/ref/create_cast.sgml

-<!-- doc/src/sgml/ref/create_cast.sgml -->
+<!--
+doc/src/sgml/ref/create_cast.sgml
+PostgreSQL documentation
+-->
 
 <refentry id="sql-createcast">
  <indexterm zone="sql-createcast">

doc/src/sgml/ref/create_collation.sgml

-<!-- doc/src/sgml/ref/create_collation.sgml -->
+<!--
+doc/src/sgml/ref/create_collation.sgml
+PostgreSQL documentation
+-->
 
 <refentry id="sql-createcollation">
  <indexterm zone="sql-createcollation">

doc/src/sgml/ref/create_conversion.sgml

-<!-- doc/src/sgml/ref/create_conversion.sgml -->
+<!--
+doc/src/sgml/ref/create_conversion.sgml
+PostgreSQL documentation
+-->
 
 <refentry id="sql-createconversion">
  <indexterm zone="sql-createconversion">

doc/src/sgml/ref/create_foreign_table.sgml

-<!-- doc/src/sgml/ref/create_foreign_table.sgml -->
+<!--
+doc/src/sgml/ref/create_foreign_table.sgml
+PostgreSQL documentation
+-->
 
 <refentry id="sql-createforeigntable">
  <indexterm zone="sql-createforeigntable">

doc/src/sgml/ref/create_function.sgml

 <!--
 doc/src/sgml/ref/create_function.sgml
+PostgreSQL documentation
 -->
 
 <refentry id="sql-createfunction">

doc/src/sgml/ref/create_procedure.sgml

 <!--
 doc/src/sgml/ref/create_procedure.sgml
+PostgreSQL documentation
 -->
 
 <refentry id="sql-createprocedure">

doc/src/sgml/ref/create_transform.sgml

-<!-- doc/src/sgml/ref/create_transform.sgml -->
+<!--
+doc/src/sgml/ref/create_transform.sgml
+PostgreSQL documentation
+-->
 
 <refentry id="sql-createtransform">
  <indexterm zone="sql-createtransform">

doc/src/sgml/ref/drop_cast.sgml

-<!-- doc/src/sgml/ref/drop_cast.sgml -->
+<!--
+doc/src/sgml/ref/drop_cast.sgml
+PostgreSQL documentation
+-->
 
 <refentry id="sql-dropcast">
  <indexterm zone="sql-dropcast">

doc/src/sgml/ref/drop_collation.sgml

-<!-- doc/src/sgml/ref/drop_collation.sgml -->
+<!--
+doc/src/sgml/ref/drop_collation.sgml
+PostgreSQL documentation
+-->
 
 <refentry id="sql-dropcollation">
  <indexterm zone="sql-dropcollation">

doc/src/sgml/ref/drop_conversion.sgml

-<!-- doc/src/sgml/ref/drop_conversion.sgml -->
+<!--
+doc/src/sgml/ref/drop_conversion.sgml
+PostgreSQL documentation
+-->
 
 <refentry id="sql-dropconversion">
  <indexterm zone="sql-dropconversion">

doc/src/sgml/ref/drop_foreign_table.sgml

-<!-- doc/src/sgml/ref/drop_foreign_table.sgml -->
+<!--
+doc/src/sgml/ref/drop_foreign_table.sgml
+PostgreSQL documentation
+-->
 
 <refentry id="sql-dropforeigntable">
  <indexterm zone="sql-dropforeigntable">

doc/src/sgml/ref/drop_transform.sgml

-<!-- doc/src/sgml/ref/drop_transform.sgml -->
+<!--
+doc/src/sgml/ref/drop_transform.sgml
+PostgreSQL documentation
+-->
 
 <refentry id="sql-droptransform">
  <indexterm zone="sql-droptransform">

doc/src/sgml/ref/load.sgml

 <!--
 doc/src/sgml/ref/load.sgml
+PostgreSQL documentation
 -->
 
 <refentry id="sql-load">

doc/src/sgml/ref/pg_config-ref.sgml

-<!-- doc/src/sgml/ref/pg_config-ref.sgml -->
+<!--
+doc/src/sgml/ref/pg_config-ref.sgml
+PostgreSQL documentation
+-->
 
 <refentry id="app-pgconfig">
  <indexterm zone="app-pgconfig">

doc/src/sgml/ref/pg_restore.sgml

-<!-- doc/src/sgml/ref/pg_restore.sgml -->
+<!--
+doc/src/sgml/ref/pg_restore.sgml
+PostgreSQL documentation
+-->
 
 <refentry id="app-pgrestore">
  <indexterm zone="app-pgrestore">

doc/src/sgml/ref/pgarchivecleanup.sgml

-<!-- doc/src/sgml/ref/pgarchivecleanup.sgml -->
+<!--
+doc/src/sgml/ref/pgarchivecleanup.sgml
+PostgreSQL documentation
+-->
 
 <refentry id="pgarchivecleanup">
  <indexterm zone="pgarchivecleanup">

doc/src/sgml/ref/pgbench.sgml

-<!-- doc/src/sgml/ref/pgbench.sgml -->
+<!--
+doc/src/sgml/ref/pgbench.sgml
+PostgreSQL documentation
+-->
 
 <refentry id="pgbench">
  <indexterm zone="pgbench">

doc/src/sgml/ref/pgtestfsync.sgml

-<!-- doc/src/sgml/ref/pgtestfsync.sgml -->
+<!--
+doc/src/sgml/ref/pgtestfsync.sgml
+PostgreSQL documentation
+-->
 
 <refentry id="pgtestfsync">
  <indexterm zone="pgtestfsync">

doc/src/sgml/ref/pgtesttiming.sgml

-<!-- doc/src/sgml/ref/pgtesttiming.sgml -->
+<!--
+doc/src/sgml/ref/pgtesttiming.sgml
+PostgreSQL documentation
+-->
 
 <refentry id="pgtesttiming">
  <indexterm zone="pgtesttiming">

doc/src/sgml/ref/pgupgrade.sgml

-<!-- doc/src/sgml/ref/pgupgrade.sgml -->
+<!--
+doc/src/sgml/ref/pgupgrade.sgml
+PostgreSQL documentation
+-->
 
 <refentry id="pgupgrade">
  <indexterm zone="pgupgrade">

doc/src/sgml/ref/set_constraints.sgml

-<!-- doc/src/sgml/ref/set_constraints.sgml -->
+<!--
+doc/src/sgml/ref/set_constraints.sgml
+PostgreSQL documentation
+-->
+
 <refentry id="sql-set-constraints">
  <indexterm zone="sql-set-constraints">
   <primary>SET CONSTRAINTS</primary>

doc/src/sgml/ref/set_session_auth.sgml

-<!-- doc/src/sgml/ref/set_session_auth.sgml -->
+<!--
+doc/src/sgml/ref/set_session_auth.sgml
+PostgreSQL documentation
+-->
+
 <refentry id="sql-set-session-authorization">
  <indexterm zone="sql-set-session-authorization">
   <primary>SET SESSION AUTHORIZATION</primary>

doc/src/sgml/ref/set_transaction.sgml

-<!-- doc/src/sgml/ref/set_transaction.sgml -->
+<!--
+doc/src/sgml/ref/set_transaction.sgml
+PostgreSQL documentation
+-->
+
 <refentry id="sql-set-transaction">
  <indexterm zone="sql-set-transaction">
   <primary>SET TRANSACTION</primary>