Document the logger option

doc/src/manual/cowboy_http.asciidoc

@@ -23,6 +23,7 @@ opts() :: #{
     idle_timeout            => timeout(),
     inactivity_timeout      => timeout(),
     linger_timeout          => timeout(),
+    logger                  => module(),
     max_empty_lines         => non_neg_integer(),
     max_header_name_length  => non_neg_integer(),
     max_header_value_length => non_neg_integer(),
@@ -78,6 +79,10 @@ Time in ms that Cowboy will wait when closing the connection. This is
 necessary to avoid the TCP reset problem as described in the
 https://tools.ietf.org/html/rfc7230#section-6.6[section 6.6 of RFC7230].
 
+logger (error_logger)::
+
+The module that will be used to write log messages.
+
 max_empty_lines (5)::
 
 Maximum number of empty lines before a request.
@@ -133,6 +138,7 @@ Ordered list of stream handlers that will handle all stream events.
 
 == Changelog
 
+* *2.7*: The `logger` option was added.
 * *2.6*: The `chunked`, `http10_keepalive`, `proxy_header` and `sendfile` options were added.
 * *2.5*: The `linger_timeout` option was added.
 * *2.2*: The `max_skip_body_length` option was added.

doc/src/manual/cowboy_http2.asciidoc

@@ -25,6 +25,7 @@ opts() :: #{
     inactivity_timeout             => timeout(),
     initial_connection_window_size => 65535..16#7fffffff,
     initial_stream_window_size     => 0..16#7fffffff,
+    logger                         => module(),
     max_concurrent_streams         => non_neg_integer() | infinity,
     max_connection_buffer_size     => non_neg_integer(),
     max_connection_window_size     => 0..16#7fffffff,
@@ -104,6 +105,10 @@ Initial window size in bytes for new streams. This is the total amount
 of data (from request bodies for example) that may be buffered
 by a single stream before the user code explicitly requests it.
 
+logger (error_logger)::
+
+The module that will be used to write log messages.
+
 max_concurrent_streams (infinity)::
 
 Maximum number of concurrent streams allowed on the connection.
@@ -234,6 +239,7 @@ too many `WINDOW_UPDATE` frames.
          to protect against various flood scenarios; and
          `stream_window_data_threshold` to control how small
          the DATA frames that Cowboy sends can get.
+* *2.7*: The `logger` option was added.
 * *2.6*: The `proxy_header` and `sendfile` options were added.
 * *2.4*: Add the options `initial_connection_window_size`,
          `initial_stream_window_size`, `max_concurrent_streams`,