add HACKING file pointing to the wiki

diff --git a/HACKING b/HACKING
new file mode 100644 (file)
index 0000000..778244f
--- /dev/null
+++ b/HACKING
@@ -0,0 +1,2 @@
+See http://live.gnome.org/Empathy/ about coding style conventions.
+See also http://live.gnome.org/Empathy/Git to read about our git workflow.