Adding information to the team page as part of onboarding task

Summary

Adds my GitLab username (amsingh6) to the team roster of the Database Excellence page as part of my onboarding tasks.

What changed

• content/handbook/engineering/data-engineering/database-excellence/_index.md: appended amsingh6 to the existing {{< group-by-slugs ... >}} shortcode for the Database Excellence team.

Why only a username is needed

The group-by-slugs shortcode (layouts/_shortcodes/group-by-slugs.html) treats each argument as a team-member slug and looks the person up in the company-wide team dataset (site.Data.public.team) with where site.Data.public.team "slug" "eq" .. It then renders the name, GitLab profile link, and role from that record. Because my details already exist in the team data, adding the slug is enough for my name and role to appear in the generated table. No hardcoded personal information is added to the handbook page.

Author checklist

• Username matches my entry in the team dataset
• Handbook pipeline passes and the rendered table shows my name and role