website/docs-dev: add initial translation docs

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

website/developer-docs/translation.md

@@ -0,0 +1,29 @@
+---
+title: Translation
+---
+
+Translation in authentik is done in two places. Most of the text is defined in the frontend in `web/`, and a subset of messages is defined in the backend.
+
+The frontend uses [lingui](https://lingui.js.org/), and the backend uses the built-in django translation tools.
+
+## Frontend
+
+If you want to translate the frontend to a new language, ensure the language code is in the `package.json` file in `web/`:
+
+```json
+    // [...]
+    "lingui": {
+        // [...]
+        "locales": [
+            "en",
+            "pseudo-LOCALE",
+            "a-new-locale"
+        ],
+    // [...]
+```
+
+Afterwards, run `npx lingui extract` to generate a base .po file.
+
+The .po files can be edited by any text editor, or using a tool such as [POEdit](https://poedit.net/).
+
+To see the change, run `npm run watch` in the `web/` directory.

website/sidebarsDev.js

@@ -8,5 +8,9 @@ module.exports = {
             type: "doc",
             id: "api",
         },
+        {
+            type: "doc",
+            id: "translation",
+        },
     ],
 };