add otel as separate module (#10)

Reviewed-on: #10
Co-authored-by: andrey <andrey@4devs.io>
Co-committed-by: andrey <andrey@4devs.io>

handler/otel/level.go

@@ -0,0 +1,16 @@
+package otel
+
+//go:generate stringer -type=Level -linecomment -output=level_string.go
+
+type Level int
+
+const (
+	levelDebug  Level = 5  // DEBUG
+	levelInfo   Level = 9  // INFO
+	levelInfo2  Level = 10 // INFO2
+	levelWarn   Level = 13 // WARN
+	levelError  Level = 17 // ERROR
+	levelError2 Level = 18 // ERROR2
+	levelError3 Level = 19 // ERROR3
+	levelFatal  Level = 21 // FATAL
+)