Illustration > Add simple circle checkmark (small)

Purpose

Add small checkmark illustration to support https://gitlab.com/gitlab-org/modelops/anti-abuse/team-tasks/-/issues/2.

Screenshots

Checklist

For a new icon and/or illustration:

• Link to related design issue:
• If this adds an icon ensure that it follows the new icon checklists.
• If this adds an illustration ensure that it follows the new illustration checklists.

For third-party trademarks:

• If this adds or updates an icon or illustration that includes a third-party trademark, ensure that it follows the process for adding third-party trademarks to GitLab.

Closes #308 (closed)