Don’t rely on Drush in the instructional modal for adding and installing a module

Problem/Motivation

The only concern the group had with the instructional modal for adding and installing a module is the fact that Drupal isn’t shipping with Drush by default.

While most people will be using the Package Manager as soon as #3312289: Svelte UI for install controllers lands, the instructional modal will be still in place for sites where the Package Manager module is not installed. Some of those website might have Drush not installed. Then there are also solutions like simplytest.me where you don’t have command line access necessarily. For the former it is at least certain that command line access is available since the installation of Drupal requires Composer.
If you take now a look at the second section in the modal you have a sentence with a visit the module page-link suggesting the user to visit /admin/modules for installing the module. That sentence is visually a lot smaller with a lot less affordance and might go unnoticed compared to the big code block with the line how to install the module with Drush.

For the record the issue was identified and initially discussed during #3312892: Drupal Usability Meeting 2022-10-07. The issue has a link to the recording of the meeting. The attendees were @AaronMcHale, @benjifisher, @narendraR, @rkoller, @shaal, @simohell, @srishtiiee, @Utkarsh_33, and @worldlinemine.

Steps to reproduce

- Go to /admin/modules/browse and click one of the Download buttons

Proposed resolution

• Add an action link button (see the Drupal Design System) that takes the user to the modules page instead of using a simple sentence with a link like currently. To get some design feed back in that regard might be useful.
• Additional steps that were discussed but with not a clear consensus yet.
• • remove the drush pm code block
  • instead of removing the code block add the instruction how to install Drush instead

Review steps

Go to /admin/modules/browse, click one of the Download buttons, and ensure the following concerns from this issue summary and follow-up comments have been adequately addressed:

• The visit the module page link
• ...should stand out more, visually
• ...should be a button
• ...should be outside, not inside, of a sentence
• The Drush instructions
• ...should have wording similar to If Drush is not installed this will add the tool to your codebase.
• ...should have the code snippet composer require drush/drush
• ...should have "Drush" capitalized consistently

Remaining tasks

• ✅ File an issue about this project
• ☐ Manual Testing
• ☐ Code Review
• ☐ Accessibility Review
• ☐ Automated tests needed/written?