update readme

README.md

@@ -10,3 +10,27 @@ In order to install the plugin, simply run: `bin/plugin -install elasticsearch/e
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     | master                   | 0.18 -> master |
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+
+A `phonetic` token filter that can be configured with different `encoder` types: `metaphone`, `soundex`, `caverphone`, `refined_soundex`, `double_metaphone` (uses "commons codec":http://jakarta.apache.org/commons/codec/api-release/org/apache/commons/codec/language/package-summary.html).
+
+The `replace` parameter (defaults to `true`) controls if the token processed should be replaced with the encoded one (set it to `true`), or added (set it to `false`).
+
+    {
+        "index" : {
+            "analysis" : {
+                "analyzer" : {
+                    "my_analyzer" : {
+                        "tokenizer" : "standard",
+                        "filter" : ["standard", "lowercase", "my_metaphone"]
+                    }
+                },
+                "filter" : {
+                    "my_metaphone" : {
+                        "type" : "phonetic",
+                        "encoder" : "metaphone",
+                        "replace" : false
+                    }
+                }
+            }
+        }
+    }