Create or update help topics that cover CKEditor 5's module overview text in hook_help()

Summary

In #3121340: Fix up minor copy problems in help topics, we've collected a number of issues related to updating help topics. That issue has been turned into a "plan" with separate issues being created.

Original report from #3121340: Fix up minor copy problems in help topics:

• On #3150364: Add a description for the language toolbar button to the CKEditor help page some text is being added to the CKEditor hook_help about the Language button that can be added to the toolbar. We need to make sure that information is also in our CKEditor topic or in an appropriate multilingual topic, or both, once that issue is finalized.

  In looking into the above, I noticed that there is a lot of info in ckeditor5's hook_help() implementation (its module overview) that is not covered adequately -- or at all -- by any existing help topic.

• On #3150364: Add a description for the language toolbar button to the CKEditor help page they also made a list of accessibility features and a section about making accessible text. I'm not sure we covered that well in our topic on Accessibility, so we should check. See this screenshot of the output of one of the patches:
  

Problem/Motivation

CKEditor's hook_help() implementation in core/modules/ckeditor5.module creates a module overview that covers:

1. An overview of the module including its uses
2. Migrating an Existing Text Format to CKEditor 5
3. Additional migration considerations for text formats with restricted HTML

Currently, we have 1 topic, editor.overview, which provides steps to configuring CKEditor5 as a text editor. There is a lot of information in ckeditor.module implementation of hook_help() that is not covered by this topic or any other.

We need to look at CKEditor5's module overview (viewable in the UI at admin/help/ckeditor5 or in code at core/modules/ckeditor5/ckeditor5.module in function ckeditor5_help()) and ensure that all of the information provided in this module overview is covered in relevant existing topics or new topics.

Note that depending on the state of Help Topics' merge into Help module and moving topics into respective module's, help topics may exist in the following locations:

• core/modules/help_topics/help_topics
• core/modules/help/help_topics
• core/modules/MODULE/help_topics

Steps to reproduce

(These are more like steps to view help topics or module overviews.)

Note: To view help topics at admin/help, Help Topics module must be enabled, or if it has been merged into Help module, Help module must be enabled.

1. Install the latest version of Drupal
2. Install CKEditor5 module (built in to Drupal 10)
3. Install Help and Help Topics (if it is still a separate experimental module)
4. Read the CKEditor5 Module Overview (go to admin/help or from the Manage menu, click on Help; look in the Module Overviews section; click on the link text CKEditor 5)
5. To view help topics, look under the Topics section.
6. To search for help topics, configure search for Help (see the help topic admin/help/topic/help.help_topic_search)

Proposed resolution

Review CKEditor 5's module overview (admin/help/ckeditor5) and make a plan for creating or updating topics.

It looks like at least 2 topics will need to be created: 1) a top-level ckeditor5.overview which describes the module and its uses; 2) a task topic with steps that covers "Migrating an Existing Text Format to CKEditor 5".

Look at the module overview's section "Additional migration considerations for text formats with restricted HTML" and see if that information can be integrated into an existing topic.

See if any other topics should be updated with information from CKEditor 5's module overview.

Update the issue summary, once a plan is decided upon.

Remaining tasks

1. Make a plan for moving info from ckeditor5's module overview into topics
2. Create a merge request with the new and updated topics (be sure to have a fresh pull of the latest version of Drupal and the correct locations of the help topics)
3. Review, approve, commit.

User interface changes

None

API changes

None

Data model changes

None

Release notes snippet

The information in CKEditor 5's module overview (its hook_help() implementation) has been integrated into new and existing help topics. The following help topics have been created and/or updated...