README.md in embulk-output-ftp-0.1.5 vs README.md in embulk-output-ftp-0.1.6

@@ -17,11 +17,11 @@
 - **port**: FTP server port number (integer, default: `21`. `990` if `ssl` is true and `ssl_explicit` is false)
 - **user**: user name to login (string, optional)
 - **password**: password to login (string, default: `""`)
 - **path_prefix** prefix of target files (string, required)
 - **sequence_format** Format for sequence part of output files (string, default: `".%03d.%02d"`)
-- **ext** e.g. "csv.gz, json.gz" (string, required)
+- **file_ext** e.g. "csv.gz, json.gz" (string, required)
 - **passive_mode**: use passive mode (boolean, default: true)
 - **ascii_mode**: use ASCII mode instead of binary mode (boolean, default: false)
 - **ssl**: use FTPS (SSL encryption). (boolean, default: false)
 - **ssl_explicit** use FTPS(explicit) instead of FTPS(implicit). (boolean, default:true)
 - **ssl_verify**: verify the certification provided by the server. By default, connection fails if the server certification is not signed by one the CAs in JVM's default trusted CA list. (boolean, default: true)
@@ -52,11 +52,11 @@
   type: ftp
   host: ftp.example.net
   port: 21
   user: anonymous
   path_prefix: /ftp/file/path/prefix
-  ext: csv
+  file_ext: csv
   formatter:
     type: csv.gz
     header_line: false
   encoders:
   - {type: gzip}
@@ -74,11 +74,11 @@
 
   ssl: true
   ssl_verify: false
 
   path_prefix: /ftp/file/path/prefix
-  ext: csv
+  file_ext: csv
 ```
 
 FTPS encryption with server certificate verification:
 
 ```yaml
@@ -104,10 +104,10 @@
       ...
       ...
       -----END CERTIFICATE-----
 
   path_prefix: /ftp/file/path/prefix
-  ext: csv
+  file_ext: csv
 ```
 
 ## Build
 
 ```