BUG #15966: Docs:

The following bug has been logged on the website:

Bug reference:      15966
Logged by:          Thomas Güttler
Email address:      guettliml@thomas-guettler.de
PostgreSQL version: 11.5
Operating system:   Linux
Description:

On this page I read this: 

https://www.postgresql.org/docs/current/functions-matching.html

> If you have pattern matching needs that go beyond this, consider writing a
user-defined function in Perl or Tcl.

I think Perl and Tcl are no more the most common languages to write
user-defined functions.

Maybe just remove "in Perl or Tcl" and provide a link to the general docs of
user-defined functions.