[ADD]: add new page in CRM

docs/crm/index.rst

@@ -10,3 +10,4 @@ Organize the pipeline
    :maxdepth: 1
 
    plan_activities.rst
+   lost_opportunities.rst

docs/crm/lost_opportunities.rst

@@ -0,0 +1,42 @@
+.. _lostopportunities:
+
+=========================
+Manage lost opportunities
+=========================
+While working with your opportunities, you might lose some of them. You will want to keep track of the reasons you lost them and also which ways Odoo can help you recover them in the future.
+
+Mark a lead as lost
+-------------------
+While in your pipeline, select any opportunity you want and you will see a *Mark Lost* button.
+
+You can then select an existing *Lost Reason* or create a new one right there.
+
+.. image:: images/crm_04.png
+   :align: center
+
+.. tip:: You will find your *Lost Reasons* under :menuselection:`Configuration --> Lost Reasons`. You can select & rename any of them as well as create a new one from there.
+
+Retrieve lost opportunities
+---------------------------
+To retrieve lost opportunities and do actions on them (send an email, make a feedback call, etc.), select the *Lost* filter in the search bar.
+
+.. image:: images/crm_05.png
+   :align: center
+
+You will then see all your lost opportunities. If you want to refine them further, you can add a filter on the *Lost Reason*.
+
+For Example, *Too Expensive*.
+
+.. image:: images/crm_06.png
+   :align: center
+
+Restore lost opportunities
+--------------------------
+
+From the Kanban view with the filter(s) in place, you can select any opportunity you wish and work on it as usual. You can also restore it by clicking on *Archived*.
+
+.. image:: images/crm_07.png
+   :align: center
+
+.. seealso::
+   * :doc:`plan_activities`