Point to gerrit.googlesource.com/gitiles/ in templates and docs.

Change-Id: I5026c07dae1908b285f16261be6af0976ca969cc

README.md

diff --git a/README.md b/README.md
index 4bb030d..bdeba97 100644
--- a/README.md
+++ b/README.md
@@ -14,6 +14,11 @@
 `gitiles.config`. Refer to the [configuration documentation](/Documentation/config.md)
 for details.
 
+## Bugs
+
+Use the [issue tracker at github](https://github.com/google/gitiles/issues) to
+file bugs.
+
 ## Contributing to Gitiles
 
 Please refer to the [Developer Guide](/Documentation/developer-guide.md).