docs: add crowdin (#3381)

docs/contributing/translations.md

@@ -0,0 +1,28 @@
+---
+layout: default
+title: Translations
+parent: Contributing
+nav_order: 6
+---
+
+# Translations
+
+Authelia has translations for many using facing areas of the web portal. Contributing to these translations is a very
+easy process.
+
+The way the translation process is facilitated is via [Crowdin]. We encourage members of the community to
+[join the Authelia Crowdin project](https://crwd.in/authelia) and help translate their preferred language.
+
+## Adding a New Language
+
+If the language you wish to translate is not on [Crowdin] then you can either reach out to one of the maintainers and
+ask them to add it or you may make a pull request directly on GitHub. The translation files are stored within 
+[this directory](https://github.com/authelia/authelia/tree/master/internal/server/locales).
+
+## Overrides
+
+Users can override translations easily locally using the [assets](../configuration/server.md#locales) directory. This is
+useful if you wish to perform a translation and see if it looks correct in the browser.
+
+
+[Crowdin]: https://crowdin.com/project/authelia