Improving contribute guides

[ced (Cédric Krier)]

@pokoli

I have a modified version of upload.py script which sets the prefix based on the folder name (which is the repository name). How can I upload it to our codereview server?

I can not updated anymore the instance. I think it is linked to Can not update backends · Issue #578 · rietveld-codereview/rietveld · GitHub
But I would prefer to infest time on Replace Rietveld (#2178) · Issues · Tryton / Tryton · GitLab