Introducing ticketing style guide

Why is this change being made?

Support Engineers spend most of their time handling tickets. This MR is introducing a style guide for Zendesk ticketing, where we'll eventually gather and document the best practices for efficient ticket handling and better queue collaboration within the team.

This change was initially introduced in !52414 (closed) but the pipelines are refusing the succeed, so I'm trying to fix this here.

Author Checklist

• Correct MR template applied (e.g blog post)
• Provided a concise title for the MR
• Added a description to this MR explaining the reasons for the proposed change, per say-why-not-just-what
• Assign this change to the correct DRI
  • If the DRI for the page/s being updated isn’t immediately clear, then assign it to your manager.
  • 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 relate to any part of the project other than updates to content and/or data files please make sure to ping @gl-static-site-editor in a comment for a review and merge. For example changes to .gitlab-ci.yml, JavaScript/CSS/Ruby code or the layout files.

For help with failing pipelines reach out in #mr-buddies in Slack