Merge branch 'docs/missing-package' into 'master'

[Docs] Add missing package

See merge request !1295

docs/admin/10_install.rst

@@ -57,6 +57,7 @@ Install some packages from the Debian package system.
                chromium \
                chromium-driver \
                redis-server \
+               pkg-config \
                postgresql \
                locales-all \
                celery