README.adoc in relaton-ieee-1.16.1 vs README.adoc in relaton-ieee-1.16.2

@@ -21,17 +21,28 @@
 
     $ gem install relaton-ieee
 
 == Usage
 
-=== Search for a standard using keywords
+=== Configuration
 
+Configuration is optional. The available option is `logger` which is a `Logger` instance. By default, the logger is `Logger.new($stderr)` with `Logger::WARN` level. To change the logger level, use `RelatonIeee.configure` block.
+
 [source,ruby]
 ----
 require 'relaton_ieee'
 => true
 
+RelatonIeee.configure do |config|
+  config.logger.level = Logger::DEBUG
+end
+----
+
+=== Search for a standard using keywords
+
+[source,ruby]
+----
 item = RelatonIeee::IeeeBibliography.search("IEEE 528-2019")
 => #<RelatonIeee::IeeeBibliographicItem:0x00007fe12ebc8cb8
 ...
 ----
 
@@ -71,11 +82,11 @@
 
 === Get document by reference
 [source,ruby]
 ----
 RelatonIeee::IeeeBibliography.get("IEEE 528-2019")
-[relaton-ieee] ("IEEE 528-2019") fetching...
-[relaton-ieee] ("IEEE 528-2019") found IEEE 528-2019
+[relaton-ieee] (IEEE 528-2019) fetching...
+[relaton-ieee] (IEEE 528-2019) found `IEEE 528-2019`
  => #<RelatonIeee::IeeeBibliographicItem:0x007fceb52a6e40
  ...
 ----
 
 === Typed links