Issue #12: code refactoring

Issue #19: added "search block form", "search no results" and "search results" support

Issue #12: added image styles support

Create composer.json

Please include a composer.json so we can use composer to get this module.

Clean-up \Drupal\styleguide\Form\StyleguideForm

Translation fixes

Generator changes

* upstream/8.x-1.x:
  Issue #6: Use \Drupal\Component\Utility\Random in the generator to generate random text and image.
  Issue #3: Use ->t() instead of t() in OO code.
  Issue #5: Update defaultStyleguide Plugin label key.

* upstream/8.x-1.x:
  Issue #5: Create styleguide Base plugin.
  Make local tasks working

Making local tasks work

* upstream/8.x-1.x:
  Issue #2: Use dependency injection instead of \Drupal::... in StyleguideLocalTasks Plugin.
  Issue #2: use dependency injection instead of \Drupal::... in OO code.
  Issue #5: Convert hook_styleguide implementations into plugins.

Replace global styleguide functions by a styleguide.generator service.