Update Readme about transit_model HOT 3 CLOSED

let transit_data = transit_model::gtfs::read_from_path("./example/", None, None, false).expect("impossible to read GTFS");

// get a stop by it's ID
let stop_area_idx = transit_data
    .stop_areas
    .get_idx("stoparea:1")
    .expect("impossible to find stop area");

println!("routes passing by stop stoparea:1");

// efficiently get all the routes that pass through the stop_area
for route in transit_data
    // The rust typesystem is able to guess that we are looking for the routes linked to the stop
    // because the Idx are strongly typed, thus route_idx is Idx<Route>
    .get_corresponding_from_idx(stop_area_idx)
    .into_iter()
    .map(|route_idx| &transit_data.routes[route_idx])
{
    println!(" - {}", route.name);
}