v0.1.6 fix to formatter and sanitizer for async use, doc update

constant.go

@@ -28,6 +28,8 @@ const (
 	FlagShowTimestamp  = formatter.FlagShowTimestamp
 	FlagShowLevel      = formatter.FlagShowLevel
 	FlagStructuredJSON = formatter.FlagStructuredJSON
+	FlagNoTimestamp    = formatter.FlagNoTimestamp
+	FlagNoLevel        = formatter.FlagNoLevel
 	FlagDefault        = formatter.FlagDefault
 )
 
@@ -54,4 +56,5 @@ const (
 	// Factors to adjust check interval
 	adaptiveIntervalFactor float64 = 1.5 // Slow down
 	adaptiveSpeedUpFactor  float64 = 0.8 // Speed up
-)
+)
+