Function set_event 

pub(crate) fn set_event(
    qt: &CxxQtThread<Sioul>,
    shared: &Arc<Shared>,
    key: &str,
    value: &str,
) -> Result<(), String>

An event’s own reminder changed from its details, for every time it comes (value: “” as usual, “none”, “15”): written into its file and sent, as its form saves it.