Perform validation to ensure that the three parameters, NumCounters, …

…MaxCost, and BufferItems, are all greater than 0.(hypermodeinc#378)

cache.go

@@ -168,10 +168,16 @@ func NewCache[K Key, V any](config *Config[K, V]) (*Cache[K, V], error) {
 	switch {
 	case config.NumCounters == 0:
 		return nil, errors.New("NumCounters can't be zero")
+	case config.NumCounters < 0:
+		return nil, errors.New("NumCounters can't be negative number")
 	case config.MaxCost == 0:
 		return nil, errors.New("MaxCost can't be zero")
+	case config.MaxCost < 0:
+		return nil, errors.New("MaxCost can't be be negative number")
 	case config.BufferItems == 0:
 		return nil, errors.New("BufferItems can't be zero")
+	case config.BufferItems < 0:
+		return nil, errors.New("BufferItems can't be be negative number")
 	case config.TtlTickerDurationInSec == 0:
 		config.TtlTickerDurationInSec = bucketDurationSecs
 	}