The following documentation comment has been logged on the website:
Page: https://www.postgresql.org/docs/13/config-setting.html
Description:
include_dir 'directory'
it it not 100% clear whether the include_dir option also allows 'if_exists'
funtionality.
I think a include_dir_if_exists should be possible.
If it is it should be expressed specifically in the docs.
If the functionality does not exist this should be mentioned very clear
in the docs also