Add translation badge to readme

Author: NilsJacobsen

README.md

@@ -236,6 +236,8 @@ There are several ways to help.
 
 8. **[Translations](https://github.com/johannesjo/super-productivity/tree/master/src/assets/i18n), Icons, etc.**: You don't have to be programmer to help. Some of the icons really need improvement and many of the translations could use some love.
 
+[![inlang status badge](https://badge.inlang.com/?url=github.com/johannesjo/super-productivity)](https://fink.inlang.com/github.com/johannesjo/super-productivity?ref=badge)
+
 9. **[Sponsor the project](https://github.com/sponsors/johannesjo)**
 
 ### Running the development server