Update community section of the DIB page

Why is this change being made?

We recently created a new section in the Community Relations handbook page about DIB: https://about.gitlab.com/handbook/marketing/community-relations/#-community-diversity-inclusion-and-belonging

We created this in order to specifically call attention to our efforts to build a more inclusive and diverse wider GitLab community.

We'd like to link to this new section from the existing Community section of the DIB handbook.

While going through that section, I've also updated the text to clarify a few things and bring attention to the main programs it seems like that section is meant to highlight: the Diversity Scholarship program and the First Look program.

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)