Change main component target folder

[stephannv]

This will make the main components be generated inside their folder instead app/components/ruby_ui.

Running rails g ruby_ui:component Alert
Before:

- app/
  - components/
    - ruby_ui/
      - alert.rb
      - alert/
        - alert_description.rb
        - alert_title.rb

After:

- app/
  - components/
    - ruby_ui/
      - alert/
        - alert.rb
        - alert_description.rb
        - alert_title.rb

Since we have Rails.autoloaders.main.collapse(Rails.root.join("app/components/ruby_ui/*")), this folder organization doesn't change how we consume the components.

[cirdes]

@stephannv , everything inside the folder is better!