test(log): add comprehensive benchmarks

Adds a new benchmark_test.go file with comprehensive benchmarks for the logging library:

Serial benchmarks:
- Trace, Debug, Info, Notice, Warn, Error levels

Formatted logging:
- Debugf, Infof, Errorf variants

Parallel benchmarks:
- DebugParallel, InfoParallel, InfofParallel

Logger instance (namespaced):
- LoggerInfo, LoggerInfof, LoggerDebugParallel

Multiple clients/namespaces:
- MultipleClients, MultipleNamespaces

Message size comparison:
- Short, Medium, Long messages

Level filtering overhead:
- DebugFilteredByLevel

Also removes the duplicate BenchmarkDebugSerial from log_test.go and applies minor whitespace formatting fixes.

Fixes #6

main.go

@@ -17,21 +17,21 @@ func generateLogs() {
 	apiLogger := logger.NewLogger("api")
 	dbLogger := logger.NewLogger("database")
 	authLogger := logger.NewLogger("auth")
-	
+
 	for {
 		logger.Info("This is a default namespace log!")
 		apiLogger.Info("API request received")
 		apiLogger.Debug("Processing API call")
-		
+
 		dbLogger.Info("Database query executed")
 		dbLogger.Warn("Slow query detected")
-		
+
 		authLogger.Info("User authentication successful")
 		authLogger.Error("Failed login attempt detected")
-		
+
 		logger.Trace("This is a trace log in default namespace!")
 		logger.Warn("This is a warning in default namespace!")
-		
+
 		time.Sleep(2 * time.Second)
 	}
 }