[devhelp/repo-cleanup: 5/7] Rename "HACKING" file

[Emmanuele Bassi <ebassi src gnome org>]

commit 3b90890271d801ed35b7dea628d58d604ffc8d64
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Mon Apr 12 14:22:42 2021 +0100

    Rename "HACKING" file
    
    GitLab recognises the presence of a "CONTRIBUTING.md" and links it from
    the project's main page.

 HACKING => CONTRIBUTING.md | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
---
diff --git a/HACKING b/CONTRIBUTING.md
similarity index 100%
rename from HACKING
rename to CONTRIBUTING.md