Put screenshot in readme.md

[jeromeetienne]

Easier to see plugins output

[jeromeetienne]

Why not in homepage?

Yeah homepage better

Not mutually exclusive, maybe. Homepage authoritative, readme only best ones

[jeromeetienne]

Sorre image in www/images/plugins/plugindirname.png

Script to convert image to proper resolution

Pluginsdirname.png

Plugindirname-original.png

[jeromeetienne]

done