Update README.md

Author: markusjwetzel

README.md

@@ -1,2 +1,106 @@
-# babel-plugin-intlized-components
-:earth_americas: Babel plugin for intlized-components
+# 🌎 babel-plugin-intlized-components
+
+Babel plugin for package [intlized-components](https://github.com/ProAI/intlized-components). The primary use case for this plugin is to extract message ids and default messages from all files of a project.
+
+## Installation
+
+```shell
+npm install babel-plugin-intlized-components
+# or
+yarn add babel-plugin-intlized-components
+```
+
+## Usage
+
+Add the plugin to your babel configuration:
+
+```json
+{
+  "plugins": ["babel-plugin-styled-components"]
+}
+```
+
+### Message extraction
+
+```javascript
+import babel from '@babel/core';
+
+// Define fileName and babelConfig variables here.
+
+const { metadata: result } = babel.transformFileSync(fileName, babelConfig);
+const { translations } = result['intlized-components'];
+
+// Do something with the translations, e.g. save them in file.
+```
+
+## Docs
+
+### Options
+
+#### `customImportKey`
+
+If you don't import `createDict` from `intlized-components` directly, you can set a custom import key in the babel plugin, so that `createDict` is detected anyway.
+
+Example:
+
+In babel configuration:
+
+```json
+{
+  "plugins": [
+    [
+      "babel-plugin-styled-components",
+      { "customImportKey": "my-custom-import" }
+    ]
+  ]
+}
+```
+
+In a file:
+
+```javascript
+import { createDict } from 'my-custom-import';
+
+const dict = createDict(...);
+```
+
+#### `autoResolveKey`
+
+Normally you have to set a key as the first parameter and a message object as the second parameter for `createDict`. If you set this option to the base path of your application, the babel plugin will derive the first parameter from the file name, so that you can call `createDict` with a message object only.
+
+Example:
+
+Without `autoResolveKey` option:
+
+```javascript
+const dict = createDict('welcome.Welcome', {
+  hello: 'Hello',
+});
+```
+
+With `autoResolveKey` option:
+
+In babel configuration:
+
+```json
+{
+  "plugins": [
+    ["babel-plugin-styled-components", { "autoResolveKey": "path-to-my-app" }]
+  ]
+}
+```
+
+In file `welcome/Welcome.js`:
+
+```javascript
+// Babel will transform createDict and will add the key "welcome.Welcome" as first parameter to the function call.
+const dict = createDict({
+  hello: 'Hello',
+});
+```
+
+_Hint: You can even set a key manually if this option is on, so you can mix up auto resolved and manually set keys._
+
+## License
+
+This package is released under the [MIT License](LICENSE).