[refactor] Extracted `computeRegression` from `renderBurndownChart` (8m)
[feature] Added multiple regression lines to show projections based on velocity over the last 2 and 3 sprints respectively
[improvement] Rounded effort up so that decimal points aren't shown on effort in the burndown chart (2m)
[improvement] Milestone: indicated whether tickets have been released or closed through styling (20m)
[fix] Estimate Effort: prevented the mousewheel from spinning an estimate up or down (5m)
[improvement] Milestones: affixed the list of milestones so that it scrolls with you (10m)