Compliance for email signature in Germany

Why is this change being made?

On slack, @leipert raised the warning that we should comply and add company details in the signature.

The employees of the German entity are supposed to have an email signature that list the full company name, address, where the company is registered and also the current Managing Director(s).
If one doesn’t comply with this, there could be fines of up to 5000 EUR. The reason behind this is, that emails of employees are considered official business correspondence, especially when dealing with external parties, e.g. customers, but maybe even folks doing interviews.

Quick German source on the topic: https://www.anwalt.de/rechtstipps/gmbh-was-muss-bei-der-email-signatur-unbedingt-beachtet-werden_157853.html

This MR add some details about this to the handbook page for the GitLab German entity

Author Checklist

• Provided a concise title for this Merge Request (MR)
• Added a description to this MR explaining the reasons for the proposed change, per 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.
• Assign reviewers for this MR to the correct Directly Responsible Individual/s (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
• If the changes affect team members, or warrant an announcement in another way, please consider posting an update in #whats-happening-at-gitlab linking to this MR
  • If this is a change that directly impacts the majority of global team members, it should be a candidate for #company-fyi. Please work with internal communications and check the handbook for examples.

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