Fix README.md

Author: ufechner7

README.md

@@ -70,10 +70,9 @@ am::AtmosphericModel = AtmosphericModel(set)
 
 @info "Ground wind speed: $(am.set.v_wind) m/s"
 
-wf::WindField = WindField(am, am.set.v_wind)
 x, y, z = 20.0, 0.0, 200.0
 t = 0.0
-vx, vy, vz = get_wind(wf, am, x, y, z, t)
+vx, vy, vz = get_wind(am, x, y, z, t)
 @time get_wind(am, x, y, z, t)
 @info "Wind at x=$(x), y=$(y), z=$(z), t=$(t): v_x=$(vx), v_y=$(vy), v_z=$(vz)"
 @info "Wind speed: $(sqrt(vx^2 + vy^2 + vz^2)) m/s"