[1.7.x] Fixed #18108 -- Added instructions for translating documentation.

Thanks Claude Paroz.

Backport of 1a3bec4a26 from master

docs/internals/contributing/localizing.txt

@@ -64,3 +64,14 @@ Django source tree, as for any code change:
 .. _Transifex: https://www.transifex.com/
 .. _Django project page: https://www.transifex.com/projects/p/django/
 .. _Transifex User Guide: http://support.transifex.com/
+
+.. _translating-documentation:
+
+Documentation
+-------------
+
+There is also an opportunity to translate the documentation, though this is a
+huge undertaking to complete entirely (you have been warned!). We use the same
+`Transifex tool <https://www.transifex.com/projects/p/django-docs/>`_. The
+translations will appear at ``https://docs.djangoproject.com/<language_code>/``
+when at least the ``docs/intro/*`` files are fully translated in your language.

docs/internals/contributing/writing-documentation.txt

@@ -372,3 +372,9 @@ one of the following:
 * Find synonyms that the spell checker recognizes.
 * If, and only if, you are sure the word you are using is correct - add it
   to ``docs/spelling_wordlist`` (please keep the list in alphabetical order).
+
+Translating documentation
+-------------------------
+
+See :ref:`Localizing the Django documentation <translating-documentation>` if
+you'd like to help translate the documentation into another language.