Add COPYRIGHT advice and indent correctly

__init__.py

@@ -1,7 +1,6 @@
 # The COPYRIGHT file at the top level of this repository contains the full
 # copyright notices and license terms.
 from trytond.pool import Pool
-
 from .model import *
 
 

invoice.xml

@@ -1,4 +1,6 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0"?>
+<!-- The COPYRIGHT file at the top level of this repository contains the full
+     copyright notices and license terms. -->
 <tryton>
     <data>
         <!-- Filters -->
@@ -210,7 +212,6 @@
             <field name="name">Account Name</field>
         </record>
 
-
         <!-- account.invoice.line -->
         <record model="babi.expression" id="account_invoice_line">
             <field name="ttype">float</field>
@@ -697,7 +698,6 @@
         </record>
 
         <!-- account.invoice.line -->
-
         <!-- Year - Product - Month | Subtotal -->
         <record model="babi.report" id="invoice_line_year_product_month">
             <field name="parent_menu" ref="babi.menu_babi"/>
@@ -1035,6 +1035,5 @@
             <field name="aggregate">sum</field>
             <field name="sequence">2</field>
         </record>
-
    </data>
 </tryton>