Update Fulfillment Roadmap Prioritization - Product Alignment - Round 2

This MR updates the Fulfillment Roadmap based off feedback in the Fulfillment Roadmap Prioritization - Product Alignment - Round 2. Full agenda / recording is available here: https://docs.google.com/document/d/1iOl7pDc6AAYwL7TRvSlOA_dQQwbJxUZ7P0A33_V6f7U/edit#heading=h.3oba92wnkcd1

I've also decided to simplify the table in the handbook to only show the top-level initiatives while providing a link to the Google spreadsheet for more details.

Author Checklist

• 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
  • Copy/paste the Slack conversation to document it for later, or upload screenshots. Verify that no confidential data is added.
• Assign reviewers for this change to the correct DRI(s)
  • 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 in on the page being edited.
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• 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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