Add example for Checksum for Contribution Pages for Membership Renewals

Add example for Checksum for Contribution Pages for Membership Renewals

docs/common-workflows/tokens-and-mail-merge.md

@@ -84,6 +84,12 @@ Create a link in the CiviMail message that includes the checksum token `{contact
 -   Joomla!: `http://example.org/index.php?option=com_civicrm&task=civicrm/contribute/transact&reset=1&id=IDNUMBER&{contact.checksum}&cid={contact.contact_id}`
 -   WordPress: `http://example.org/?page=CiviCRM&q=civicrm/contribute/transact&reset=1&id=IDNUMBER&{contact.checksum}&cid={contact.contact_id}`
 
+**Checksum for Contribution Pages for Membership Renewals**: To send people to a contribution page for membership renewals use this path where `IDNUMBER` is the ID of your contribution page. This is typically used in Scheduled Reminders for membership renewals, where  the `membership.id` will be evaluated to the membership to be renewed:
+
+-   Drupal: `http://example.org/civicrm/contribute/transact?reset=1&id=IDNUMBER&{contact.checksum}&cid={contact.contact_id}&mid={membership.id}`
+-   Joomla!: `http://example.org/index.php?option=com_civicrm&task=civicrm/contribute/transact&reset=1&id=IDNUMBER&{contact.checksum}&cid={contact.contact_id}&mid={membership.id}`
+-   WordPress: `http://example.org/?page=CiviCRM&q=civicrm/contribute/transact&reset=1&id=IDNUMBER&{contact.checksum}&cid={contact.contact_id}&mid={membership.id}`
+
 **Checksum for standard Profiles** (edit mode): To send people to a profile use this path where `IDNUMBER` is the ID of the Profile you want to send them to:
 
 -   Drupal: `http://example.org/civicrm/profile/edit?reset=1&gid=IDNUMBER&{contact.checksum}&id={contact.contact_id}`