added few helper scripts

[henrikac]

This PR adds a few bash scripts that abstracts away a lot of the long docker compose commands, e.g.:

Now, if you want to reset the database, you'll have to write up to three different docker compose commands

• docker compose stop web
• docker compose run web bundle exec rake db:reset
• docker compose start web

but with the new db script you just have to run ./db reset.

The scripts also checks whether docker compose is available, otherwise docker-compose will be used.

New scripts

• psql => docker compose exec db psql -U postgres ConfBuddies_development
• rails-c => docker compose run --rm web bin/rails c
• rspec => docker compose run --rm web bundle exec rspec
• rubocop => docker compose run --rm web bundle exec rubocop
• db => This script comes with three commands; setup, migrate and reset. (./db <command>)