Product 880 north star

Why is this change being made?

Following Product#880 (comment 303193552)

We want all the product groups to have a North Star Metric. This change adds a very quick introduction, highlight the core points of the North Star Metric, and helps PMs to start working with it.

Does this MR meet the acceptance criteria?

Assign to DRI

• Did you assign this change to the correct DRI of the page or information you are changing?

Conformity

• Added description to this MR explaining the reasons for the proposed change, per say-why-not-just-what