Update charging_station.json - Added QCode for reveo

[ckpiper]

No description provided.

[UKChris-osm]

Did you mean to replace fx with fr?

[ckpiper]

I was not sure if fx was code for something that I was unaware of. Thus I left it.

[UKChris-osm]

The Country Code fx refers to mainland France only, whereas fr includes mainland France and other French territories. If Reveo only operate within mainland France, you can keep it as simply fx, if not, you can remove fx and use fr instead.