VSOP: The variable star one-shot project I. Project presentation and first data release by Dall, T, Foellmi, C, Pritchard, J, Lo Curto, G, Allende Prieto, C, Bruntt, H, Amado, P, Arentoft, T, Baes, M, Depagne, E, Fernandez, M, Ivanov, V, Koesterke, L, Monaco, L, O'Brien, K, Sarro, L, Saviane, I, Scharwächter, J, Schmidtobreick, L, Schütz, O, Seifahrt, A, Selman, F, Stefanon, M, Sterzik, M