Delta values should be supported when entering hit points on actor sheets

[happydevil37]

Request to be able to adjust the HP value on the character sheet buy using - and + to calculate the value.

This feature is similar to the way that adjusting the HP value works on the token.

Reason: Running face to face games using foundry, we use physical dice and miniatures. I use the character sheet to track spells, hit points, and attack rolls, and being able to adjust the hit points of a creature from the character sheet would save a lot of time.

Function: Typing in - or + into the Hit point field and then a number will recalculate the hit points of the creature. When the value reaches 0 then the creature can have the dead condition.
This is the way that the PF1 system works.

I would also be just as happy with a macro similar to the pf2e workbench conditions manager.