Fix typo, add translation doc link

CONTRIBUTING.md

-Thanks for for contributing! Please see the [Contributor Guide](https://jupyter-docker-stacks.readthedocs.io) in the 
-documentation for information about how to contribute [package updates](http://jupyter-docker-stacks.readthedocs.io/en/latest/contributing/packages.html),
+Thanks for contributing! Please see the
+[Contributor Guide](https://jupyter-docker-stacks.readthedocs.io) in the documentation for
+information about how to contribute
+[package updates](http://jupyter-docker-stacks.readthedocs.io/en/latest/contributing/packages.html),
 [recipes](http://jupyter-docker-stacks.readthedocs.io/en/latest/contributing/recipes.html),
 [tests](http://jupyter-docker-stacks.readthedocs.io/en/latest/contributing/tests.html),
 [features](http://jupyter-docker-stacks.readthedocs.io/en/latest/contributing/features.html),
-and [community-maintained stacks](http://jupyter-docker-stacks.readthedocs.io/en/latest/contributing/stacks.html).
+[translations](https://jupyter-docker-stacks.readthedocs.io/en/latest/contributing/translations.html),
+and
+[community-maintained stacks](http://jupyter-docker-stacks.readthedocs.io/en/latest/contributing/stacks.html).