update readme and bump gem

lib/github_changelog_generator.rb

@@ -220,5 +220,7 @@ class ChangelogGenerator
 end
 
 if __FILE__ == $0
-  ChangelogGenerator.new.compund_changelog
+  changelog_generator = ChangelogGenerator.new
+  # changelog_generator.compund_changelog
+
 end

lib/github_changelog_generator/parser.rb

@@ -29,7 +29,7 @@ class Parser
       opts.on('-f', '--date-format [FORMAT]', 'Date format. Default is %d/%m/%y') do |last|
         options[:format] = last
       end
-      opts.on('-o', '--output [FORMAT]', 'Output file. Default is CHANGELOG.md') do |last|
+      opts.on('-o', '--output [NAME]', 'Output file. Default is CHANGELOG.md') do |last|
         options[:output] = last
       end
     }