Polish docs

lib/broadway_sqs/ex_aws_client.ex

@@ -1,7 +1,9 @@
 defmodule BroadwaySQS.ExAwsClient do
   @moduledoc """
   Default SQS client used by `BroadwaySQS.Producer` to communicate with AWS
-  SQS service. This client uses the `ExAws.SQS` library and implements the
+  SQS service.
+
+  This client uses the `ExAws.SQS` library and implements the
   `BroadwaySQS.SQSClient` and `Broadway.Acknowledger` behaviours which define
   callbacks for receiving and acknowledging messages.
   """

lib/broadway_sqs/options.ex

@@ -1,6 +1,6 @@
 defmodule BroadwaySQS.Options do
   @moduledoc """
-  Broadway Sqs Option definitions and custom validators.
+  Broadway SQS option definitions and custom validators.
   """
 
   def definition() do

lib/broadway_sqs/sqs_client.ex

@@ -1,6 +1,7 @@
 defmodule BroadwaySQS.SQSClient do
   @moduledoc """
   A generic behaviour to implement SQS Clients for `BroadwaySQS.Producer`.
+
   This module defines callbacks to normalize options and receive message
   from a SQS queue. Modules that implement this behaviour should be passed
   as the `:sqs_client` option from `BroadwaySQS.Producer`.
@@ -10,7 +11,21 @@ defmodule BroadwaySQS.SQSClient do
 
   @type messages :: [Message.t()]
 
+  @doc """
+  Should initialize the SQS client.
+
+  This callback is called when the producer is started. It should return
+  `{:ok, normalized_opts}` if the client was initialized successfully or
+  `{:error, reason}` if there was an error. `normalized_opts` is what gets
+  passed to the `c:receive_messages/2` callback.
+  """
   @callback init(opts :: any) :: {:ok, normalized_opts :: any} | {:error, reason :: binary}
 
+  @doc """
+  Should fetch messages from the configured SQS queue.
+
+  `opts` is the normalized options returned from `c:init/1`. The `demand`
+  argument is the number of messages that the producer is asking for.
+  """
   @callback receive_messages(demand :: pos_integer, opts :: any) :: messages
 end