Update Headings for Fulfillment Direction Page

Why is this change being made?

Part of https://gitlab.com/gitlab-org/fulfillment-meta/-/issues/351

This MR simplifies the headings used on the Fulfillment Direction page https://about.gitlab.com/direction/fulfillment/

Before

• Fulfillment Section Overview
• Principles
  • Conducting business with GitLab should be seamless
  • Build a strong foundation so GitLab can scale and other teams can collaborate more effectively
  • Use data to make decisions and measure impact
  • Iterate, especially when the impact of a change is sizeable
• Vision
  • Build a best-in-class webstore
  • Drive more self-service transactions
  • Deliver competitive purchasing options in sales-assisted and webstore orders
  • Enable channel partners and distributors to deliver experiences as good as our direct sales motions
  • Make license, consumption and user-management fully self service
• Fulfillment Section's Current Focus (FY22 Q3)
• Group Responsibilities
  • Purchase
  • License
  • Utilization
  • Additional clarity by group
• Performance Indicators
• How we prioritize

After

• Overview
• Principles
• Vision
  • Purchase
  • License
  • Utilization
• Roadmap
  • OKRs
  • Stakeholder Matrix
• Performance Indicators

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.
  • 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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