205151-match trailing slash in GitLab-Flavored Markdown References

Following #205151 (closed), trying to match a trailing slash to be included in the generated GitLab-Flavored markdown link

Screenshots

Links with trailing slashes:

Currently not matched:

After trailing slash is matched:

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done