Adopt a scoring system for issue prioritization

We have more issues than we have time or people to fix them, and therefore could use a simple scoring system to help with issue prioritization. @sajolida has successfully implemented a similar system for Tails issues in the past.

Ideas:

• Nielsen's Severity Ratings for Usability Problems.
• Sajolida's Cost x Benefit model, using a Low-Mid-High scale.
• Combine Nielsen's scoring system with the Jacobian estimation technique to create a 4x4 matrix similar to Sajolida's? e.g.
  • Severity: 1, 2, 3, 4
  • Complexity: small, medium, large, extra-large

Other considerations:

• We can use scoped labels to record each issue's final score. Labels can also be sorted in terms of priority.
• Ideally, cost would be informed by our estimation technique. Estimations can also be added separately to the issue sidebar in Gitlab.
• Migrating to Gitlab Ultimate will unlock issue weights, which is just a simple integer, but can also be used to sort issues.
• Design risk assessments is a separate but complimentary concept, following a likelihood x Impact model.