Add composer.json, fix info.yml and phpcs.xml, clean up hook_theme()

Problem/Motivation

Some standard Drupal infrastructure is missing or has minor issues.

1. Missing composer.json

The module has no composer.json. drupal.org generates one automatically, but having it in the repo is good practice for declaring metadata and PHP version requirements.

2. Missing package key in info.yml

Without a package key, the module shows up under "Other" on the Extend page. Something like package: Accessibility would make it easier to find.

3. Typo in phpcs.xml

Line 17:

<!-- Apply"Drupal" and "DrupalPractice coding standards. -->

Missing space after "Apply" and missing opening quote before "DrupalPractice".

4. hook_theme() has conflicting keys

In progressive_accessibility_widget.module, the theme definition for asw_widget sets both render element and variables:

'asw_widget' => [
  'render element' => 'element',
  'variables' => [
    'widget_icon' => NULL,
  ],
],

These two keys are mutually exclusive. When variables is set, render element is ignored. Since the template uses {{ widget_icon }}, only variables should be kept.

Proposed resolution

• Add composer.json with correct metadata and license
• Add package: Accessibility to info.yml
• Fix the phpcs.xml comment
• Remove render element from hook_theme()