[STAR-2069] Update handbook/epic_management.md
I've updated the epic description template to include project management practices as discussed in the thread https://forum.opencraft.com/t/please-review-project-management-guidelines-draft/1168/14
I've updated the epic description template to include project management practices as discussed in the thread https://forum.opencraft.com/t/please-review-project-management-guidelines-draft/1168/14