README.md in rbatch-2.1.6 vs README.md in rbatch-2.1.7

@@ -1,6 +1,6 @@
-[[English]](https://github.com/fetaro/rbatch/blob/master/README.md "english") [[Japanese]](https://github.com/fetaro/rbatch/blob/master/README.ja.md "japanese")
+[English](https://github.com/fetaro/rbatch/blob/master/README.md "english") | [Japanese ](https://github.com/fetaro/rbatch/blob/master/README.ja.md "japanese") |  [Document (YardDoc)](http://fetaro.github.io/rbatch/index.html)
 
 RBatch: Framework for Ruby-based Batch Script
 =============
 
 About RBatch (for ver 2)
@@ -29,11 +29,11 @@
     $ sudo gem install rbatch
     $ rbatch-init    # => make directories and sample scripts
     $ ruby bin/hello_world.rb
     $ cat log/YYYYMMDD_HHMMSS_hello_world.log
 
-Manual
+Overview
 --------------
 
 ### RBatch home directory
 
 When you set `${RB_HOME}` environment variable, RBatch home directory is fix at `${RB_HOME}`.
@@ -164,10 +164,15 @@
 
 ### Double Run Check
 
 Using `forbid_double_run` option, two same name scripts cannot run at the same time.
 
+Manual
+--------------
+
+Manual -> [Document (YardDoc)](http://fetaro.github.io/rbatch/index.html)
+
 Sample
 --------------
 
 ### AWS EC2 Volume Backup Script
 
@@ -364,27 +369,26 @@
 #log_stdout : false
 
 # Delete old log files
 #
 #   Default is false.
-#   If this is true, delete old log file when RBatch::Log.new is called.
-#   A log file to delete is a log file which was made by the
-#   RBatch::Log instance, and log filename format include "<date>".
+#   If this is true, delete old log files when RBatch::Log.new is called.
+#   If log filename format does not include "<date>", do nothing.
 #
 #log_delete_old_log : true
 #log_delete_old_log : false
 
-# Expire Date of Log Files
+# Expire Days of Log Files
 #
 #   Default is 7.
 #
 #log_delete_old_log_date : 14
 
 # Send Mail
 #
 #   Default is false.
-#   When log.error(msg) or log.fatal(msg) called , send e-mail
-#   including "msg".
+#   When log.error is called, log.fatal is called,
+#   or rescue an Exception, send e-mail.
 #
 #log_send_mail : true
 
 # Mail Parameters
 #