[pitivi] readme: Document where to look at to start hacking

[Thibault Saunier <tsaunier src gnome org>]

commit 4f179dc4cf3c7629b3fc12808468da1a40dc8c93
Author: Thibault Saunier <tsaunier igalia com>
Date:   Tue Aug 25 19:57:14 2020 -0400

    readme: Document where to look at to start hacking

 README.md | 8 ++++++++
 1 file changed, 8 insertions(+)
---
diff --git a/README.md b/README.md
index dea72c11..168bba7d 100644
--- a/README.md
+++ b/README.md
@@ -13,3 +13,11 @@ For the list of dependencies, look at [pitivi/check.py](pitivi/check.py)
 
 Your involvement is what keeps this project moving forward.
 See the "contributing" section of <http://www.pitivi.org> to get started.
+
+# Hacking
+
+See the [contributing](http://www.pitivi.org/?go=contributing) section to get
+started.
+
+Come [talk to us](http://www.pitivi.org/?go=contact) so we coordinate
+to get the most out of it.