Transmutes Instant Potions of Health to Potion of Regeneration.
The healing is (by default) +50% of the source potion, but (by default) delivered over 15 seconds rather than instantly.
Gameplay Effects
This allows players much more time between using each potion, and they can generally just use the hotbar, thus players do not require elite inventory management skills to manage their potion consumption while fighting.
Also since fewer potions are needed, there is less grind time required to get supplied for a battle.
This is probably the most important feature in TownyCombat for unlock combat for regular players, or at least equally as important as Battlefield Roles.
This PR adds the Potion Transmuter
Closes #73