Missing member documentation

[Matthew Cain]

Fields and methods are missing documentation comments.

For example method InventoryItem#getCurrentCondition() is missing documentation.

API doc:

public float getCurrentCondition()

Return the real condition of the weapon, based on this calcul : Condition/ConditionMax * 100

Returns:
    float 

Compiled:

---@public
---@return float
function InventoryItem:getCurrentCondition() end

[Matthew Cain]

Resolved by #72 and #73.