Add ACER Report on Peak shaving products to literature

[KrainerD]

Summary: Peak-shaving products should only be used in energy crisis situations. Using them under normal circumstances has too many drawbacks which outweigh the positive points.

https://www.acer.europa.eu/electricity/expert-group-peak-shaving-products

https://www.acer.europa.eu/sites/default/files/documents/Publications/ACER-report-impact-peak-shaving-products-normal-market-conditions-2025.pdf