Provide a semantic bundle configuration

[mpdude]

Instead of having to set up service configuration like this:

<service id="webfactory.shortcode.your-shortcode-name" parent="Webfactory\ShortcodeBundle\Handler\EmbeddedShortcodeHandler.inline" class="Webfactory\ShortcodeBundle\Handler\EmbeddedShortcodeHandler">
    <argument index="1">reference-to-your-replacement-controller</argument>
    <tag name="webfactory.shortcode" shortcode="your-shortcode-name"/>
</service>

... and using the Webfactory\ShortcodeBundle\Handler\EmbeddedShortcodeHandler.inline or Webfactory\ShortcodeBundle\Handler\EmbeddedShortcodeHandler.esi parent services, with this PR you can instead write:

# config.yml
webfactory_shortcode:
  shortcodes:
    my-shortcode: 'My\Handling\Controller::method'
    another-shortcode:
      controller: 'My\Handling\Controller::method'
      method: esi

The first is a shorthand notation to register the my-shortcode shortcode which will be rendered with the inline strategy. The second is a bit more elaborate, but allows to specify esi as the rendering strategy.

[mpdude]

Thank you for the exhaustive review!