documentation updates

docs/features/i18n.md

@@ -1,3 +1,78 @@
 # Internationalization (i18n)
 
-Coming soon...
+The Content Application provides support for the following languages:
+
+- German (`de`)
+- English (`en`)
+- Spanish (`es`)
+- French (`fr`)
+- Italian (`it`)
+- Japanese (`ja`)
+- Norwegian (`nb`)
+- Dutch (`nl`)
+- Brazilian Portuguese (`pt-BR`)
+- Russian (`ru`)
+
+The fallback locale is the English one, however current browser language is taken as the default one automatically when the application starts.
+
+## User-defined language
+
+You can allow users to set custom language that gets saved to user preferences.
+The main application menu already has the [ADF Language Menu](https://github.com/Alfresco/alfresco-ng2-components/blob/development/docs/language-menu.component.md) component integrated and pre-filled with the supported items.
+
+To change the default language set edit the `app.config.json` file and add or remove items:
+
+```json
+{
+    ...,
+    "languages": [
+        {
+            "key": "de",
+            "label": "German"
+        },
+        {
+            "key": "en",
+            "label": "English"
+        },
+        {
+            "key": "es",
+            "label": "Spanish"
+        },
+        ...
+    ]
+}
+```
+
+The file is located at the following path: `/src/app.config.json`.
+
+## Custom languages
+
+To add a custom language, add a new "JSON" file to the "/src/assets/i18n" folder
+with the name of the target locale, for instance, a "de.json" for the "German".
+
+Translate the resource strings based on the default "en.json" file.
+You can copy the content over to your newly created file and replace English values with translated text.
+
+```json
+{
+  "APP": {
+    "SIGN_IN": "Anmelden",
+    "SIGN_OUT": "Abmelden",
+    "NEW_MENU": {
+      "LABEL": "Neu",
+      "MENU_ITEMS": {
+        "CREATE_FOLDER": "Ordner erstellen",
+        "UPLOAD_FILE": "Datei hochladen",
+        "UPLOAD_FOLDER": "Ordner hochladen"
+      },
+      ...
+    }
+  },
+  ...
+}
+```
+
+The Content Application automatically bundles your file upon project build.
+You can test your locale by changing the browser language settings and reloading the page.
+
+Optionally, you can extend the [ADF Language Menu](https://github.com/Alfresco/alfresco-ng2-components/blob/development/docs/language-menu.component.md) component with the newly added language by updating the `app.config.json` file.