Hi Montanhès,

no worries, I have fixed the tagging: https://www.openstreetmap.org/changeset/160363420

I used https://overpass-turbo.eu to find all nodes with "name"="Plug" and "shop"="electrical", then opened the result in JOSM and changed the tags.

If you ever have a question, feel free to ask :-) 
Also, the forums are a great place to get information and help: https://community.openstreetmap.org 