Update dhelfand Information

Why is this change being made?

This pull request adds a photo and social media profiles for Daniel Helfand.

CHANGEME

Author and Reviewer Checklist

Please verify the check list and ensure to tick them off before the MR is merged.

• Provided a concise title for this [Merge Request (MR)][mr]
• Added a description to this MR explaining the reasons for the proposed change, per [say why, not just what][say-why-not-just-what]
  • Copy/paste the Slack conversation to document it for later, or upload screenshots. Verify that no confidential data is added, and the content is [SAFE][SAFE]
• Assign reviewers for this MR to the correct [Directly Responsible Individual/s (DRI)][dri]
  • If the DRI for the page/s being updated isn’t immediately clear, then assign it to one of the people listed in the Maintained by section on the page being edited
  • If your manager does not have merge rights, please ask someone to merge it AFTER it has been approved by your manager in [#mr-buddies][mr-buddies-slack]
  • The [when to get approval][when-to-get-approval] handbook section explains the workflow in more detail
• For transparency, share this MR with the audience that will be impacted.
  • Team: For changes that affect your direct team, share in your group Slack channel
  • Department: If the update affects your department, share the MR in your department Slack channel
  • Company: If the update affects all (or the majority of) GitLab team members, post an update in [#whats-happening-at-gitlab][whats-happening-at-gitlab-slack] linking to this MR
    • For high-priority company-wide announcements work with the [internal communications][internal-communications] team to post the update in [#company-fyi][company-fyi-slack] and align on a plan to circulate in additional channels like the ["While You Were Iterating" Newsletter][engagement-channels]

Commits

• update dhelfand info