[ADD] rental: add customer signature page

content/applications/sales/rental.rst

@@ -141,4 +141,5 @@ Odoo always uses two rules to compute the price of a product when a rental order
    rental/products
    rental/service_products
    rental/manage_deposits
+   rental/customer_signature
 

content/applications/sales/rental/customer_signature.rst

@@ -0,0 +1,64 @@
+==================
+Customer signature
+==================
+
+Odoo can request that the customer sign a rental or service agreement. Rental agreements outline the
+terms between the company and the customer before the customer picks up the rental products. Such
+documents can ensure everything is returned on time and in its original condition.
+
+Service agreements detail the business relationship and mutual duties. These agreements protect both
+the provider and the customer by creating clear, enforceable guidelines. Ideally, they should be
+signed **before** any work begins or the pickup of any rental products.
+
+App integration configuration
+=============================
+
+This feature requires the :doc:`Sign <../../productivity/sign>` app to be installed to be available.
+The :guilabel:`Request Signature` feature allows the customer to sign the document via email or the
+customer portal. The customer cannot sign the document through the user's **Sign** app.
+
+Requesting a signature
+======================
+
+If signatures are required, go to the **Rental** app and from the default :guilabel:`Rental Orders`
+dashboard, select the desired rental order. Go to the :icon:`fa-cog` :guilabel:`(Actions)` icon, and
+click :guilabel:`Request Signature`.
+
+.. image:: customer_signature/request-signature.png
+   :alt: The Request Signature option in the Odoo Rental application.
+
+A *New Signature Request* pop-up window displays. Select the desired document from the
+:guilabel:`Template` drop-down menu.
+
+.. image:: customer_signature/sign-documents-popup.png
+   :alt: The Sign Documents pop-up window that appears in the Odoo Rental application.
+
+Doing so reveals a second *New Signature Request* pop-up window. Upon confirming the information in
+the form, click :guilabel:`Send` to initiate the signing process.
+
+.. image:: customer_signature/new-signature-request-form.png
+   :alt: The New Signature Request pop-up window that appears in the Odoo Rental application.
+
+A link to the signature request appears in the record's chatter. The document is accessible to the
+customer via the customer portal or email.
+
+Signing a document from an email link
+-------------------------------------
+
+When the customer clicks :guilabel:`Sign document`, a separate page is displayed, showing the
+document to be signed. The customer begins the process by clicking :guilabel:`Click to start`. The
+app guides the signer to the required signature locations and allows them to create electronic
+signatures to complete the form.
+
+.. image:: customer_signature/adopt-signature-popup.png
+   :alt: The adopt your signature pop-up window that appears in the Odoo Rental application.
+
+Once the document has been signed and completed, click :guilabel:`Validate & Send Completed
+Document` at the bottom of the document. Odoo presents the option to download the signed document
+for record-keeping purposes, if necessary.
+
+.. image:: customer_signature/validate-send-doc-button.png
+   :alt: The validate and send completed document button in the Odoo Rental application.
+
+.. seealso::
+   `Odoo Tutorials: Sign <https://www.odoo.com/slides/sign-61>`_