[gnome-calendar] HACKING: updated with contributing guidelines

[Erick Pérez Castellanos <erickpc src gnome org>]

commit 6635f314226b85cb574f352264502f65b6f2d2ec
Author: Erick Pérez Castellanos <erick red gmail com>
Date:   Wed Jan 21 09:29:49 2015 -0500

    HACKING: updated with contributing guidelines

 HACKING |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)
---
diff --git a/HACKING b/HACKING
index 202c690..5d4c190 100644
--- a/HACKING
+++ b/HACKING
@@ -20,3 +20,11 @@ Code formating and ordering
 
 + Line splitting will work accordingly to Gtk+ code style, adding the following:
   1. Pure mathematic calculation can extend over the 120 pixel line
+
+Contributing guidelines
+=======================
+
++ Fill a bug, attach a patch, wait for review (ping the maintainers if you think
+we took too long)
++ If you patch touch any autotools related files at all in any non trivial way,
+ensure **make distcheck** pass before posting the patch