Don't hide the free tier as a stewardship promise

Why is this change being made?

Out of the Pricing Page review today, it was proposed that for stewardship of open source offering, we should not hide or make it harder to see the Free tier.

For further context, this was suggested when the idea of separating the Free tier offering away from paid tiers on the /pricing page was brought into the agenda. It was stated that this could be seen as not in line with our stewardship balance of the open source project and capturing revenue through the paid tiers as described on https://about.gitlab.com/company/stewardship/.

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
• Assign this change to the correct 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 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 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. (this requirement has been removed pending identification of a new DRI for the handbook)