doc: call for translation

README.md

@@ -57,7 +57,7 @@ export FLASK_APP=hiboo
 flask run --reload
 ```
 
-#### Misc
+#### Translate
 
 If you create or update messages in the `python`/`html` source files, don't forget to update the messages catalogs:
 ```sh
@@ -65,6 +65,8 @@ pybabel extract -F babel.cfg -o messages.pot hiboo/
 pybabel update -i messages.pot -d hiboo/translations/
 ```
 
+If you wish to contribute to the translation of Hiboo, join us on [the dedicated Weblate repository](https://glotte.felinn.org/projects/hiboo/forge-tedomum-hiboo/)
+
 ### Test instance
 
 Our test instance is running at: https://auth.test.tedomum.net