Add hydro storage in Faroe Islands (FO 🇫🇴 )

[Manu1400]

In zone FO we use a public JSON API with some negatives values:

  "Vatnid":"-3,56",
  "Lomundaroyri":"-1,49",
  "Heygadalur":"-1,26",
  "Eidisvatn":"-4,29",
  "Strandadalur":"-1,91",
  "Ryskisvatn":"-0,60",
  "Vatnsnesvatn":"-0,60"

Lomundaroyri is a reservoir in Streymoy.

Vatnsnesvatn is the name of lake for Botnur power plant, a hydroelectric power station

=> I think it's a hydro storage

Notes

ElectricityMap say Faroe Islands have 49.0MW hydro storage capacity