Provide dedicated element #help property

Problem

Providing inline help has become a common best practice. It is possible to use place 'help text' in an elemen's #description but the #description property has limitations. Interactive inline help should be handled via dedicated #help property.

Solution

Provide dedicated element #help property.

Tasks

• Tweak webform.help.css namespacing
• Add #help to admin UI.
• Create 'webform_element_help' Twig template.
• Add help support to webform_preprocess_form_element_label()
• Add #help to translatable properties.
• Build test form.
• Update style-guide.
• Write basic tests.

References

• https://www.uxmatters.com/mt/archives/2007/05/dynamic-help-in-web-forms.php
• https://baymard.com/blog/inline-help

CSS namespace

• webform-element-help