This commit adds redirections to files moved in odoo/documentation-user#524 (13.0):
- sales/sale_amazon.rst moved to sales/amazon_connector.rst
- sales/sale_amazon/apply.rst moved to sales/amazon_connector/apply.rst
- sales/sale_amazon/setup.rst moved to sales/amazon_connector/setup.rst
- sales/sale_amazon/manage.rst moved to sales/amazon_connector/manage.rst
- sales/sale_ebay.rst moved to sales/ebay_connector.rst
- sales/ebay/setup.rst moved to sales/ebay_connector/setup.rst
- sales/ebay/manage.rst moved to sales/ebay_connector/manage.rst