feat: variable decay time oxygen timer (#17)

config/client.lua

@@ -2,5 +2,6 @@ return {
     startingOxygenLevel = 100,
     putOnSuitTimeMs = 5000,
     takeOffSuitTimeMs = 5000,
-    refillTankTimeMs = 5000
-}
+    refillTankTimeMs = 5000,
+    decayRate = 1, -- The rate at which the oxygen level decays. Defaults to 1.
+}