Example repository using milestones for PTCs

• Each PTC is represented by a milestone that can have an optional due date and description. Note the description is unformatted text, not markdown
• The current state of the PTCs are visible in the main issue list by clicking on the milestones button.
• Progress towards the PTC is tracked by opening issues that are assigned the milestone.
• PTC issues are handled in the same way other development issues
• PTC milestones must begin with something like "PTC:" to distinguish them from other milestones.
• Milestone templates are not available