Add Pontoon configuration file

Pontoon is the translation platform we will use in the future to translate the
extension strings. This change adds the configuration file.

Bug: twpowertools:40
Change-Id: I7775a7abf28db1f41c4ceba7bb70dc2c6711fa60
diff --git a/.zuul.yaml b/.zuul.yaml
index 328dbda..b670233 100644
--- a/.zuul.yaml
+++ b/.zuul.yaml
@@ -8,6 +8,7 @@
       - "docs/.*"
       - "OWNERS"
       - "README.md"
+      - "i18n-config.toml"
 
 - project:
     check: