Add instructions on setting Pageless as the default

Why is this change being made?

💡 Provide a detailed answer to the question on why this change is being proposed, in accordance with our value of Transparency.

A message was posted to Slack reminding team members that the pageless Google Doc format is our preference:

I'm seeing more and more Google docs that are not pageless, AMA's, meeting docs, ... The Pageless format is the GitLab preferred format, as we don't intend to print our documents. This allows to optimize the space on our screens, improves collaboration and quickly hide comments to further increase the document width.

Call for action: If you see a document that is not pageless and is not intended for print? Go to the document settings and make it so. Take a bias for action and help us improve our efficiency together

When reviewing a recent document I made I noticed it was in Pages format; I never really paid attention to the format. I also suspect I wouldn't pay much attention in future. Setting Pageless as the default is the most efficient way to stick to GitLab's preferred format.

This MR adds instructions on how to do this.

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)
• 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, and the content is SAFE
• 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
  • The 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
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