document: .i18nrc is conf file, not .babelrc (#10)

* document: .i18nrc is conf file, not .babelrc

Extracting msgids fails if no .i18nrc file is provided

* Remove extra/gettext wrapping

README.md

@@ -18,34 +18,30 @@ npm install --save signavio-i18n
 
 ## Setup
 
-Add the configuration for gettext message extraction to your `.babelrc`:
+Add a section like the following to your `packages.json`:
 
 ```json
 {
-  "extra": {
-    "gettext": {
-      "headers": "<POT_HEADERS>",
-      "fileName": "<PATH_TO_POT>",
-      "baseDirectory": "<PATH_TO_BASEDIR>"
-    }
+  "scripts": {
+    "i18n-init": "cd src/locales && msginit --no-translator --input messages.pot --locale",
+    "i18n": "i18n-extract \"src/**/*.js\" src/locales/messages.pot && i18n-merge src/locales/messages.pot src/locales/*.po"
   }
 }
 ```
 
-All available options are documented here: https://github.com/getsentry/babel-gettext-extractor
-
-
-Add a section like the following to the `packages.json`:
+Create the file `.i18nrc` and add a configuration object for gettext message extraction:
 
 ```json
 {
-  "scripts": {
-    "i18n-init": "cd src/locales && msginit --no-translator --input messages.pot --locale",
-    "i18n": "i18n-extract \"src/**/*.js\" src/locales/messages.pot && i18n-merge src/locales/messages.pot src/locales/*.po"
-  }
+  "headers": "<POT_HEADERS>",
+  "fileName": "<PATH_TO_POT>",
+  "baseDirectory": "<PATH_TO_BASEDIR>"
 }
 ```
 
+All available options are documented here: https://github.com/getsentry/babel-gettext-extractor
+
+
 ## Usage
 
 Add the translations to the PO files, and initialize the i18n module in your application using the `init` function: