Proposed change to our RICE framework documentation in the handbook

Proposed change to our RICE framework documentation in the handbook to drive consensus, alignment, and clarity when using the framework.

Depending on the part of the Product you are working on, and the target users for a specific item of work, your Reach score specifically can vary wildly compared to other stages/groups.

For example... we in Plan could implement a feature that only applies to Ultimate users, a small subset of GitLab's overall user base, however the Impact (which is a multiplier in the RICE formula) would be high due to increased customer happiness with the offering, more upgrades or renewals to the Ultimate with it's high price tag.

We could also implement a new feature to Issues which would benefit a much larger portion of the user base (Reach) but may not have as high of an Impact due to it appealing to lower tier or Free users.

Having standards to our RICE formula enable us to operate on a level playing field when calculating RICE scores and leveraging them for prioritization decisions.

The standards I have proposed are gathered from Intercoms usage of RICE which I have found to work well in the past. They are just proposals, and I'm looking for feedback and discussion to ensure we are all in agreement on the standardization.