Adding additional brand narrative

Why is this change being made?

This change is being suggested based on our conversation about how we covey the brand story. Please review and provide feedback.

Suggestions included in this MR

• Added brand vision based on our conversation. I have specifically added "brand" to make sure it isn't confused with the product vision.
  • A good article on brand vision and mission can be found here
• Added additional narrative copy to the brand to connect the mission, vision and values into the brand story
  • Reference for characteristics of a good brand -B.R.A.V.E.
• Added the concept of building an ecosystem to allow our mission and vision to be accomplished
• Added link the values page

Not included

• The WHY, WHAT, HOW
• Visuals

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)

cc: @melsmo