[gtk/ebassi/for-master: 2/3] docs: Link the contribution guide from the README

[Emmanuele Bassi <ebassi src gnome org>]

commit f1741584e6d5a69876babf15cf10ef06beca516f
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Wed Apr 29 12:49:05 2020 +0100

    docs: Link the contribution guide from the README
    
    Hopefully people will read it.

 README.md | 6 ++++++
 1 file changed, 6 insertions(+)
---
diff --git a/README.md b/README.md
index a4ec1a0452..3915049aa3 100644
--- a/README.md
+++ b/README.md
@@ -140,6 +140,12 @@ In the bug report please include:
 * Further information such as stack traces may be useful, but
   is not necessary.
 
+Contributing to GTK
+-------------------
+
+Please, follow the [contribution guide](./CONTRIBUTING.md) to know how to
+start contributing to GTK.
+
 Release notes
 -------------