Replace prazdnikisegodnyaru with celebratoday, small underhood fixes

- Replace prazdnikisegodnyaru with celebratoday as first is banned in Russia
- Update .golangci.yml rule set
- Megatons of fixes for linter
- Update README.md

internal/log/log.go

@@ -1,3 +1,4 @@
+// Package log implements logging facility as golang slog module wrapper.
 package log
 
 import (
@@ -33,9 +34,9 @@ func Init(level string, fileDescriptor *os.File) {
 
 	opts := &slog.HandlerOptions{
 		// Use the ReplaceAttr function on the handler options
-		// to be able to replace any single attribute in the log output
+		// to be able to replace any single attribute in the log output.
 		ReplaceAttr: func(groups []string, a slog.Attr) slog.Attr { //nolint: revive
-			// check that we are handling the time key
+			// Check that we are handling the time key.
 			if a.Key != slog.TimeKey {
 				return a
 			}
@@ -62,7 +63,7 @@ func Init(level string, fileDescriptor *os.File) {
 	)
 }
 
-// Error passes message directly to slog.Error().
+// Error passes message directly to [slog.Error()].
 func Error(message string) {
 	slog.Error(message)
 }
@@ -72,7 +73,7 @@ func Errorf(format string, a ...any) {
 	slog.Error(fmt.Sprintf(format, a...))
 }
 
-// Warn passes message directly to slog.Warn().
+// Warn passes message directly to [slog.Warn()].
 func Warn(message string) {
 	slog.Warn(message)
 }
@@ -82,7 +83,7 @@ func Warnf(format string, a ...any) {
 	slog.Warn(fmt.Sprintf(format, a...))
 }
 
-// Info passes message directly to slog.Info().
+// Info passes message directly to [slog.Info()].
 func Info(message string) {
 	slog.Info(message)
 }
@@ -92,7 +93,7 @@ func Infof(format string, a ...any) {
 	slog.Info(fmt.Sprintf(format, a...))
 }
 
-// Debug passes message directly to slog.Debug().
+// Debug passes message directly to [slog.Debug()].
 func Debug(message string) {
 	slog.Debug(message)
 }