[gedit] readme: add development resources section

[Sébastien Wilmet <swilmet src gnome org>]

commit 3600a92cfff742dea52958e13917d0ad5f68262b
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Mon May 4 23:21:02 2020 +0200

    readme: add development resources section
    
    To have less stuff on the wiki.

 README.md | 9 +++++++++
 1 file changed, 9 insertions(+)
---
diff --git a/README.md b/README.md
index 393d2f89b..a924b8042 100644
--- a/README.md
+++ b/README.md
@@ -44,6 +44,15 @@ Please read
 it contains a list of frequently reported bugs and a link to the bug
 tracker.
 
+Development resources
+---------------------
+
+- [gedit on GitLab](https://gitlab.gnome.org/GNOME/gedit)
+- [gedit-plugins on GitLab](https://gitlab.gnome.org/GNOME/gedit-plugins)
+- [Tarballs](https://download.gnome.org/sources/gedit/)
+- [Roadmap](docs/roadmap.md)
+- [gedit wiki attic](https://wiki.gnome.org/Apps/Gedit/Attic)
+
 Contributions
 -------------