add some comment on customer

src/Models/Customer.php

@@ -14,6 +14,11 @@ use TypeError;
  * the account validation status. You can use it as
  * a standalone class but beware of catching exceptions
  *
+ * Be warned that on server side data is normalized
+ * - firstname and lastname are 'capitalized'
+ * - fields are trimmed
+ * - non numeric chars are removed from postcode
+ *
  * @property string $hashcode The crm hashcode this is a readonly field
  * @property string $email Must be a rfc valid email on a valid domain name
  * @property string $password Required only on create, must have upper and lowers chars,