[ADD] CRM: Membership/Partnership module page

Co-authored-by: Felicia Kuan <feku@odoo.com>

Author: theRealThagomizer

content/applications/sales/crm/optimize.rst

@@ -11,3 +11,4 @@ Optimize your Day-to-Day work
    optimize/gamification
    optimize/utilize_activities
    optimize/lead_enrichment
+   optimize/member_partner_module

content/applications/sales/crm/optimize/member_partner_module.rst

@@ -0,0 +1,49 @@
+===============================
+Membership / Partnership module
+===============================
+
+The Membership / Partnership module allows for the creation and sale of memberships. Memberships can
+be sold through both sales orders and subscriptions products so that businesses can organize and
+interact with customers as members. This allows for:
+
+- measuring membership activity, inactivity, sign ups, and churn rates
+- viewing membership renewals and expirations
+- following up on membership dues and associated payments
+- communicating with members, including sending email blasts based on members' current status
+- assigning different membership levels to members
+- organizing members-only events
+- creating membership lists populated with contact info and other details about members.
+
+The Membership / Partnership module vs. the Membership app
+==========================================================
+
+Beginning with 19.0, the **Membership** app has been replaced by the Membership / Partnership
+module. This module captures all of the functionality of the **Membership** app, but in a module
+that is better integrated with other essential apps without requiring a specific **Accounting**
+module. This replacement does not break any existing membership information when upgrading to 19.0.
+
+App integrations with the Membership / Partnership module
+=========================================================
+
+Once activated, the Membership / Partnership module is fully integrated with both the **Sales** and
+**Subscriptions** apps. The module is also compatible with the **eCommerce** app, allowing customers
+to purchase memberships through business's websites.
+
+Finally, the Membership / Partnership module is compatible with pricelists both before and after
+sales. Price rules can be set before memberships are sold and applied after they are active.
+
+Activating the new module
+=========================
+
+The Memberships / Partnerships module can be activated within the **CRM** app. To activate the
+Memberships / Partnerships module, go to :menuselection:`CRM app --> Configuration --> Settings`. In
+the :guilabel:`CRM` section, check the :guilabel:`Membership / Partnership` box to activate the
+module. The name given to affiliates can also be customized. By default, it is set to `Members`.
+
+.. seealso::
+   - :doc:`../../../sales/sales`
+   - :doc:`../../../sales/subscriptions`
+   - :doc:`../../../sales/crm`
+   - :doc:`../../../essentials/contacts`
+   - :doc:`../../../sales/sales/products_prices/prices/pricing`
+   - :doc:`../../../websites/ecommerce`