Avoid bare URLs in YAML frontmatter in documentation

What does this MR do?

While looking at: gitlab-org/technical-writing/team-tasks#1598, I realized that our URLs in our documentation frontmatter may to look like a URL in many contexts. For example, rumdl doesn't treat these as URLs.

This MR updates the documentation YAML frontmatter in this project so that we are explicitly marking the URLs as URLs in more contexts. It doesn't change how GitLab renders the URLs, and doesn't affect one's ability to right-click on the URL and open it.

Author's checklist

• Ensure the branch name starts with docs- or ends with -docs, so only the docs-related CI jobs are included
• Consider taking the GitLab Technical Writing Fundamentals course
• Follow the:
  • Documentation process.
  • Documentation guidelines.
  • Style Guide.
• Merge Request Title and Description are up to date, accurate, and descriptive
• MR targeting the appropriate branch
• MR has a green pipeline on GitLab.com
• When ready for review, MR is labeled "~workflow::ready for review" per the Distribution MR workflow

If you are only adding documentation, do not add any of the following labels:

• ~"feature"
• ~"frontend"
• ~"backend"
• ~"bug"
• ~"database"

These labels cause the MR to be added to code verification QA issues.

Review checklist

Documentation-related MRs should be reviewed by a Technical Writer for a non-blocking review, based on Documentation Guidelines and the Style Guide.

• If the content requires it, ensure the information is reviewed by a subject matter expert.
• Technical writer review items:
  • Ensure docs metadata is present and up-to-date.
  • Ensure the appropriate labels are added to this MR.
  • If relevant to this MR, ensure content topic type principles are in use, including:
    • The headings should be something you'd do a Google search for. Instead of Default behavior, say something like Default behavior when you close an issue.
    • The headings (other than the page title) should be active. Instead of Configuring GDK, say something like Configure GDK.
    • Any task steps should be written as a numbered list.
    • If the content still needs to be edited for topic types, you can create a follow-up issue with the docs-technical-debt label.
• Review by assigned maintainer, who can always request/require the above reviews. Maintainer's review can occur before or after a technical writer review.
• Ensure a release milestone is set.