Enable release notes translation

Releasenote translation publishing is being prepared. 'locale_dirs'
needs to be defined in conf.py to generate translated version of the
release notes.

Note that this repository might not get translated release notes - or
no translations at all - but we add the entry here nevertheless to
prepare for it.

Change-Id: I428d583eb3f3bbced321348e2a71035fbb282806
diff --git a/releasenotes/source/conf.py b/releasenotes/source/conf.py
index 4522a17..140263c 100644
--- a/releasenotes/source/conf.py
+++ b/releasenotes/source/conf.py
@@ -275,3 +275,6 @@
 
 # If true, do not generate a @detailmenu in the "Top" node's menu.
 # texinfo_no_detailmenu = False
+
+# -- Options for Internationalization output ------------------------------
+locale_dirs = ['locale/']