Use a singleton pattern for logging

This change migrates the internal/logging package to a singleton
pattern. It now exports a Log variable which can be acquired from any
other package.

internal/logging/logging.go

@@ -13,10 +13,10 @@ type Logger struct {
 }
 
 var (
-	logger Logger
+	Log Logger
 )
 
-func InitLogger(appConfig *config.AppConfig) Logger {
+func InitLogger(appConfig *config.AppConfig) {
 
 	lj := &lumberjack.Logger{
 		Filename:   filepath.Join(appConfig.LogDir, appConfig.LogFile),
@@ -26,17 +26,11 @@ func InitLogger(appConfig *config.AppConfig) Logger {
 		Compress:   appConfig.LogCompression,
 	}
 
-	logger = Logger{
+	Log = Logger{
 		slog.New(
 			slog.NewJSONHandler(lj, &slog.HandlerOptions{
 				AddSource: appConfig.LogAddSource,
 			}),
 		),
 	}
-
-	return logger
-}
-
-func GetLogger() Logger {
-	return logger
 }