Odoo - add website configuration

res_config.py

class WebsiteConfigSettings(models.TransientModel):
    """Override website config model."""

    _inherit = "website.config.settings"

    my_new_field = fields.Char(
        string='My field',
        related='website_id.my_new_field'
    )

res_config_view.xml

<openerp>
  <data>

<record id="website_config_settings" model="ir.ui.view">
  <field name="name">website settings form</field>
  <field name="model">website.config.settings</field>
  <field name="inherit_id" ref="website.view_website_config_settings"/>
  <field name="arch" type="xml">

    <xpath expr="//group[@name='advanced']" position="after">
      <group string="MY section" name="my-section">
        <field name="my_new_field" />
      </group>
    </xpath>

  </field>
</record>

  </data>
</openerp>

website.py

class Website(models.Model):
    """Override website model."""

    _inherit = "website"

    my_new_field = fields.Char('My field')

website_view.xml

<?xml version="1.0" encoding="utf-8"?>

<openerp>
  <data>

<record id="website_form" model="ir.ui.view">
  <field name="name">advanced website form</field>
  <field name="model">website</field>
  <field name="inherit_id" ref="website.view_website_form"/>
  <field name="arch" type="xml">

    <field name="social_github" position="replace">
      <field name="my_new_field" />
    </field>

  </field>
</record>

  </data>
</openerp>

Could you please tell me why do we need the website_view.xml?
It does not seem to affect the display at all.