💝 Let's say thanks to all translator

doc/_templates/index.html

@@ -92,8 +92,8 @@
     create a customized documentation using Sphinx written by the matplotlib
     developers.{%endtrans%}</p>
 
-  <p>{%trans%}There is a <a href="http://docs.sphinx-users.jp/">Japanese translation</a>
-    of this documentation, thanks to the Japanese Sphinx user group.{%endtrans%}</p>
+  <p>{%trans%}There is a translation team in <a href="https://www.transifex.com/sphinx-doc/sphinx-doc/dashboard/">Transifex</a>
+    of this documentation, thanks to the Sphinx document translators.{%endtrans%}</p>
   <p>{%trans%}A Japanese book about Sphinx has been published by O'Reilly:
     <a href="https://www.oreilly.co.jp/books/9784873116488/">Sphinxをはじめよう /
       Learning Sphinx</a>.{%endtrans%}</p>