Configuration method for snowpacker.cr.

Usage:

# Snowpacker::Engine.configure do |config|
  # If the dev server & extension middleware should be enabled. Ensure this is `true` when you
  # want the dev server to run. Set `false` in production.
  config.enabled = ENV["MY_SERVER_ENV"]? == "development"

  # The path `snowpack.config.js` will be loaded from.
  # config.config_path = Dir.current

  # The port requests will be redirected too. This does NOT change the port snowpack actually runs on.
  # Make sure this matches the port in your `snowpack.config.js` file. Snowpack defaults to `8080`.
  # config.port = 8080

  # The hostname requests will be redirected too. This does NOT change the hostname snowpack actually
  # runs on. Make sure this matches the hostname in your `snowpack.config.js` file.
  # Snowpack defaults to `localhost`.
  # config.hostname = "localhost"

  # The `NODE_ENV` that will be prepended to the command starting the snowpack dev server. This can
  # be overwritten via Crystal's environment variables with `ENV["NODE_ENV"] = "my_env"` if you
  # would prefer.
  #
  # Crystal nor Node can access environment variables outside of their process for safety reasons.
  # Because of this, snowpacker.cr prepends the env to the command.
  #
  # Example: `"NODE_ENV=#{Snowpacker.config.node_env} npx snowpack #{cmd}"
  # config.node_env = "development"

  # The regex snowpacker.cr uses to match assets. If a request matches this, the request will be
  # redirected to snowpacks dev server. The default regex should be fine for most use cases but
  # this configuration is exposed for advanced use cases.
  # config.asset_regex = /.(css|scss|sass|less|js|ts|jsx|tsx|ico|jpg|jpeg|png|webp|svg)/
end