README.md in embulk-output-google_spreadsheets-0.1.1 vs README.md in embulk-output-google_spreadsheets-0.2.0

@@ -7,14 +7,25 @@
 * **Plugin type**: output
 * **Load all or nothing**: no
 * **Resume supported**: no
 * **Cleanup supported**: yes
 
+## Usage
+
+### Install plugin
+
+```
+embulk gem install embulk-output-google_spreadsheets
+```
+
+
 ## Configuration
 
-- **service_account_email**: description (string, required)
-- **p12_keyfile**: description (string, required)
-- **spreadsheet_id**: description (string, required)
+- **service_account_email**: Your Google service account email (string, required)
+- **p12_keyfile**: Fullpath of private key in P12(PKCS12) format (string, required)
+- **spreadsheet_id**: Your spreadsheet id (string, required)
+- **sheet_index**: sheet index (int, optional default: 0)
+- **application_name**: Anything you like (string, optional defaulf: "Embulk-GoogleSpreadsheets-OutputPlugin")
 
 ## Example
 
 ```yaml
 out: