[IMP] website: add link to cookies bar documentation

The documentation PR https://github.com/odoo/documentation/pull/4315/
adds a new doc page about cookies bar. This commit adds a link in the
Website settings, next to the cookies bar feature.

Task-3297795

closes odoo/odoo#120718

X-original-commit: 26f41e15e79f88db39d8e9389a8cae32ddb989c3
Related: odoo/documentation#4349
Signed-off-by: Romain Derie (rde) <rde@odoo.com>
Signed-off-by: Castillo Jonathan (jcs) <jcs@odoo.com>

addons/website/views/res_config_settings_views.xml

@@ -77,7 +77,8 @@
                     </block>
 
                     <block title="Privacy" id="website_settings" attrs="{'invisible': [('website_id', '=', False)]}">
-                        <setting id="website_cookies_bar_setting" help="Display a customizable cookies bar on your website">
+                        <setting id="website_cookies_bar_setting" help="Display a customizable cookies bar on your website"
+                            documentation="/applications/websites/website/configuration/cookies_bar.html">
                             <field name="website_cookies_bar"/>
                         </setting>
                         <setting id="shared_user_account_setting" groups="website.group_multi_website" help="Accounts are usable across all your multiple websites">