add main repo info

README

@@ -2,6 +2,7 @@ This repository holds all active translations, with one branch per project.
 We have also the translation attic, for translations we don't use anymore:
 https://gitlab.torproject.org/tpo/community/translation-attic
 
-For more information, please read:
+Localization work is done at https://gitlab.torproject.org/tpo/community/l10n/
 
+For more information, please read:
 https://gitlab.torproject.org/tpo/community/l10n/-/wikis/home