pgsql-server/doc/src/sgml filelist.sgml postgr ...

CVSROOT:    /cvsroot
Module name:    pgsql-server
Changes by:    tgl@svr1.postgresql.org    03/10/22 19:28:10

Modified files:
    doc/src/sgml   : filelist.sgml postgres.sgml spi.sgml
                     trigger.sgml xfunc.sgml xplang.sgml
Added files:
    doc/src/sgml   : plhandler.sgml

Log message:
    Move docs about index cost estimation functions and writing a procedural
    language handler to the 'Internals' area, per my proposal of yesterday.
    Clean up the trigger documentation a bit.  Push SPI chapter to the end
    of its part, and reorder the Internals chapters into what seems a more
    sensible order (at the moment anyway).