[IMP] website_form: add info on email_cc field

In a website form, when "Email cc" field is added,
an i icon will be displayed besides the field label to
guide user about multiple email addresses support.

task-2074045
closes odoo/odoo#37116

Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>

addons/website_form/static/src/xml/website_form_editor.xml

@@ -8,6 +8,9 @@
                 <label class="col-form-label" t-att-for="field.name">
                     <t t-esc="field.string"/>
                 </label>
+                <span t-if="field.name == 'email_cc'" title="Separate email addresses with a comma.">
+                    <i class="fa fa-info-circle"/>
+                </span>
             </div>
             <div t-att-class="field.formatInfo and field.formatInfo.contentClass || 'col-lg-7 col-md-8'">
                 <t t-raw="0"/>