Suggestion on Document for Version 12 Section 40.3

The following documentation comment has been logged on the website:

Page: https://www.postgresql.org/docs/12/rules-materializedviews.html
Description:

Hello all,


I'm reading Section 40.3, and there is an example (the third square by
reverse order):


SELECT word FROM words ORDER BY word <-> 'caterpiler' LIMIT 10;

     word     
---------------
 cater
 caterpillar
 Caterpillar
 caterpillars
 caterpillar's
 Caterpillar's
 caterer
 caterer's
 caters
 catered
(10 rows)


As shown here https://www.postgresql.org/docs/current/pgtrgm.html, the
operator `<->` is in an additional module. Without the context, the reader
will need searching to help understand the meaning. It would be better if
further reference is given.


Yushan