The A11y provides a suite to improve accessibility on your website.

#How can i use it?
A11y module provides a set of plugins to improve the accessibility which would be use on A11y blocks. Also, you can implements a custom a11y plugin by extending from class A11yPluginBase in your custom module. You can see an example in the Keyboard plugin.

Once your plugin is created, you can implements it creating an A11y entity