Add methods to `rails console`

application.rb

module SailboatGuide
  class Application < Rails::Application
    console do
      require 'console_helpers'
      TOPLEVEL_BINDING.eval('self').extend ConsoleHelpers
    end
  end
end

console_helpers.rb

# Helper methods for `rails console`
#
#.  $ rails console
#   >> s = slug 'pacific-seacraft/25'
#   => #<Sailboat:0x00007fa2a4339480 ...>
#
module ConsoleHelpers
  def slug(path)
    Slug.by_path(path)
  end
end