Add a link to the source on git.drupalcode.org

Adding mockup:

My suggestion is to add a "Git URL" field to the Project entity that, when populated, will make the link to the source code be shown. If the link is not populated, then no link will be shown.

The MR is ready for review.

As this module is theme agnostic, it just adds the link with wrapping classes and a "git" icon. Any theme can easily format that div and icon as needed. The default look is:

If the approach here is good, we will create a Bluecheese issue to style this new element.

Yay! Great feature. I think "View file on ..." would be the proper English not "in"? Otherwise UI looks good. Did not review the code in detail.

Bluecheese issue: #3455724: Style new element in api site →

Just a little note: Code like new TranslatableMarkup('@link_to_file', ['@link_to_file' => Formatter::linkFile($file_entity)]); does not get translations. What the people who translate on localize.drupal.org see as text to translate is @link_to_file, and since that is a placeholder, they would just put @link_to_file because placeholders are not translated.

That is not really an issue is what returned from Formatter::linkFile($file_entity) is already a translated string; otherwise, $link_to_file = new TranslatableMarkup('@link_to_file', ['@link_to_file' => Formatter::linkFile($file_entity)]); will always show a link in English.

If Formatter::linkFile($file_entity) returns a translated string, then it is not necessary TranslatableMarkup, but FormattableMarkup

Changed the text to "View on" as the word "File" is just above and is not needed.

Also changed the translatable strings to use the direct value instead (I know this is not part of this issue but I'm just trying to get in as a quick fix to remote the phpcs issues).

Added a few small remarks. Nothing major so leaving at NR.

Funky, about the order. But if style-lint is happy I guess it's good ;-)