Add flask documentation

readme.md

@@ -24,3 +24,28 @@ from tcii18n import Translator
 translator = Translator('my_file.csv')
 translator.translate('My string')
 ```
+
+For using this project into a Flask application.
+You have to import `flask_methods` from `tcii18n.template`
+Create a function that return the name of the translation file.
+Call `flask_methods` with `app` and the function.
+After that, you can use the function `_` or `trans` in your template for translation.
+
+A minimal example :
+
+*core.py*
+
+```
+from tcii18n.template import flask_methods
+
+def get_translations_file():
+    return 'path/to/my/file.csv'
+
+flask_methods(app, get_translations_file)
+```
+
+*template.html*
+
+```
+<h1>{{ _("Sentence") }}</h1>
+```