docs: write godocs in Producer

Author: vvatanabe

producer.go

@@ -6,16 +6,24 @@ import (
 	"github.com/google/uuid"
 )
 
+// ProducerOptions holds configuration options for a Producer.
 type ProducerOptions struct {
+	// IDGenerator is function that generates a unique identifier for each message produced by the Producer.
+	// The default ID generator is uuid.NewString.
 	IDGenerator func() string
 }
 
+// WithIDGenerator is an option function to set a custom ID generator for the Producer.
+// Use this function to provide a custom function that generates unique identifiers for messages.
+// The default ID generator is uuid.NewString.
 func WithIDGenerator(idGenerator func() string) func(o *ProducerOptions) {
 	return func(o *ProducerOptions) {
 		o.IDGenerator = idGenerator
 	}
 }
 
+// NewProducer creates a new instance of a Producer, which is used to produce messages to a DynamoDB-based queue.
+// The Producer can be configured with various options, such as a custom ID generator.
 func NewProducer[T any](client Client[T], opts ...func(o *ProducerOptions)) *Producer[T] {
 	o := &ProducerOptions{
 		IDGenerator: uuid.NewString,
@@ -29,20 +37,29 @@ func NewProducer[T any](client Client[T], opts ...func(o *ProducerOptions)) *Pro
 	}
 }
 
+// Producer is a generic struct responsible for producing messages of any type T to a DynamoDB-based queue.
 type Producer[T any] struct {
 	client      Client[T]
 	idGenerator func() string
 }
 
+// ProduceInput represents the input parameters for producing a message.
 type ProduceInput[T any] struct {
-	Data         T
+	// Data is the content of the message to be produced. The type T allows for flexibility in the data type of the message payload.
+	Data T
+	// DelaySeconds is the delay time (in seconds) before the message is sent to the queue.
 	DelaySeconds int
 }
 
+// ProduceOutput represents the result of the produce operation.
 type ProduceOutput[T any] struct {
+	// Message is a pointer to the Message type containing information about the produced message.
 	Message *Message[T]
 }
 
+// Produce sends a message to the queue using the provided input parameters.
+// It generates a unique ID for the message using the Producer's ID generator and delegates to the Client's SendMessage method.
+// An error is returned if the SendMessage operation fails.
 func (c *Producer[T]) Produce(ctx context.Context, params *ProduceInput[T]) (*ProduceOutput[T], error) {
 	if params == nil {
 		params = &ProduceInput[T]{}