Start to set up the Vizro dashboard

cell3.py

from vizro import Vizro
import vizro.models as vm
import vizro.plotly.express as px

first_page = vm.Page(
title="Documentation traffic dashboard",
layout=vm.Layout(
    grid=[
        [0, 2],
        [1, 2], 
    ],
),
components=[
    # TO DO
    ],
)
...