* Add app colors example

* Update docs/configuring-metabase/environment-variables.md

Co-authored-by: Nemanja Glumac <31325167+nemanjaglumac@users.noreply.github.com>

* formatting

Co-authored-by: Nemanja Glumac <31325167+nemanjaglumac@users.noreply.github.com>
Co-authored-by: jeff bruemmer <jeff.bruemmer@gmail.com>

* Update config-file.md

* Update docs/configuring-metabase/config-file.md

Co-authored-by: Jeff Bruemmer <jeff.bruemmer@gmail.com>

* Update config-file.md

Co-authored-by: Jeff Bruemmer <jeff.bruemmer@gmail.com>

There are two things that needed some change:
1) default value: it's 10 secs rather than 5
2) this env var applies to both app db and external db's

* allow disabling custom geojson via env var

* add env var to docs and tweak setting description