Clarify nature of Codes values w.r.t. OTLP (#3386)

* Clarify nature of Codes values w.r.t. OTLP

* Update codes/codes.go

Co-authored-by: Damien Mathieu <42@dmathieu.com>

* go eff em tee dash ehs

Co-authored-by: Damien Mathieu <42@dmathieu.com>
Co-authored-by: Tyler Yahn <MrAlias@users.noreply.github.com>

codes/codes.go

@@ -23,10 +23,20 @@ import (
 const (
 	// Unset is the default status code.
 	Unset Code = 0
+
 	// Error indicates the operation contains an error.
+	//
+	// NOTE: The error code in OTLP is 2.
+	// The value of this enum is only relevant to the internals
+	// of the Go SDK.
 	Error Code = 1
+
 	// Ok indicates operation has been validated by an Application developers
 	// or Operator to have completed successfully, or contain no error.
+	//
+	// NOTE: The Ok code in OTLP is 1.
+	// The value of this enum is only relevant to the internals
+	// of the Go SDK.
 	Ok Code = 2
 
 	maxCode = 3