README.md in fluent-plugin-rename-key-0.1.4 vs README.md in fluent-plugin-rename-key-0.2.0

@@ -1,12 +1,11 @@
 # fluent-plugin-rename-key, a plugin for [Fluentd](http://fluentd.org)
 
 ## Status
-[![Gem Version](https://badge.fury.io/rb/fluent-plugin-rename-key.png)](http://badge.fury.io/rb/fluent-plugin-rename-key)
-[![Build Status](https://travis-ci.org/shunwen/fluent-plugin-rename-key.png?branch=master)](https://travis-ci.org/shunwen/fluent-plugin-rename-key)
-[![Coverage Status](https://coveralls.io/repos/shunwen/fluent-plugin-rename-key/badge.png?branch=master)](https://coveralls.io/r/shunwen/fluent-plugin-rename-key?branch=master)
-[![Bitdeli Badge](https://d2weczhvl823v0.cloudfront.net/shunwen/fluent-plugin-rename-key/trend.png)](https://bitdeli.com/free "Bitdeli Badge")
+[![Gem Version](https://badge.fury.io/rb/fluent-plugin-rename-key.svg)](https://badge.fury.io/rb/fluent-plugin-rename-key)
+[![Build Status](https://travis-ci.org/shunwen/fluent-plugin-rename-key.svg?branch=master)](https://travis-ci.org/shunwen/fluent-plugin-rename-key)
+[![Coverage Status](https://coveralls.io/repos/shunwen/fluent-plugin-rename-key/badge.svg?branch=master)](https://coveralls.io/r/shunwen/fluent-plugin-rename-key?branch=master)
 
 ## Overview
 
 Fluentd output plugin. Renames keys matching the given regular expressions, assign new tags, and re-emits. This plugin resembles the implementation of [fluent-plugin-rewrite-tag-filter](https://github.com/y-ken/fluent-plugin-rewrite-tag-filter).
 
@@ -34,9 +33,14 @@
 ```
 # <num> is an integer, used to sort and apply the rules
 # <key_regexp> is the regular expression used to match the keys, whitespace is not allowed, use "\s" instead
 # <new_key> is the string with MatchData placeholder for creating the new key name, whitespace is allowed
 rename_rule<num> <key_regexp> <new_key>
+
+# <num> is an integer, used to sort and apply the rules
+# <key_regexp> is the regular expression used to match the keys, whitespace is not allowed, use "\s" instead
+# <new_key> is the string to replace the matches with, with MatchData placeholder for creating the new key name, whitespace is allowed. Optional, if missing then the matches are removed
+replace_rule<num> <key_regexp> <new_key>
 
 # Optional: remove tag prefix
 remove_tag_prefix <string>
 
 # Optional: append additional name to the original tag, default is "key_renamed"