[gedit-plugins] Add CONTRIBUTING.md file for the GitHub mirror

[Sébastien Wilmet <swilmet src gnome org>]

commit c8bf022c182d11fb03598797e1c99d45080bfd78
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Fri Oct 30 14:03:49 2015 +0100

    Add CONTRIBUTING.md file for the GitHub mirror
    
    As suggested on the desktop-devel-list in May 2015.

 CONTRIBUTING.md |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)
---
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
index 0000000..8622b32
--- /dev/null
+++ b/CONTRIBUTING.md
@@ -0,0 +1,6 @@
+The GNOME contributing guidelines require patches to be forwarded to GNOME's
+Bugzilla instance hosted at https://bugzilla.gnome.org. Please do not open
+GitHub pull requests against this module as they will be ignored. More
+information is available at the following wiki page:
+
+    https://wiki.gnome.org/Sysadmin/GitHub