PostgreSQL: don't use `regconfig` and `GENERATED` column anymore /!\ pgsql schema needs to be updated /!\ /!\ Minimal PostgreSQL required version is back to 9.5 /!\ `regconfig` is using system table, and `pg_upgrade` can't handle that, causing trouble when moving to a new major version of PostgreSQL. To work around this, the `data_fts_cfg` column type in `items` has been changed from `regconfig` to `text`. GENERATED column can't be used with type casting to `regconfig`, so the data_fts column is now generated with a trigger. As a result, the minimal requirement of PostgreSQL 12 is not necessary anymore.

# Minimal makefile for Sphinx documentation
#

# You can set these variables from the command line.
SPHINXOPTS    =
SPHINXBUILD   = sphinx-build
SOURCEDIR     = .
BUILDDIR      = .build

# Put it first so that "make" without argument is like "make help".
help:
	@$(SPHINXBUILD) -M help "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)

.PHONY: help Makefile

# Catch-all target: route all unknown targets to Sphinx using the new
# "make mode" option.  $(O) is meant as a shortcut for $(SPHINXOPTS).
%: Makefile
	@$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)