[REF] developer: rewrite sql view as a howto

SQL view was formerly part of the dashboard tutorial which is now
obsolete. Since creating a SQL view as a tutorial does not make sense
anymore, it has been converted into a simple howto.

closes odoo/documentation#4034

Task: 3226581
X-original-commit: 7124542ed9
Signed-off-by: Tiffany Chang <tic@odoo.com>

content/developer/howtos.rst

@@ -14,6 +14,7 @@ How-to guides
     howtos/javascript_client_action
     howtos/web_services
     howtos/company
+    howtos/create_reports
     howtos/accounting_localization
     howtos/translations
     howtos/provide_iap_services
@@ -52,6 +53,11 @@ How-to guides
       Learn how to manage multiple companies and deal with the records-related specificities of a
       multi-company environment.
 
+   .. card:: Create customized reports
+      :target: howtos/create_reports
+
+      Learn how to create customized reports with SQL Views.
+
    .. card:: Accounting localization
       :target: howtos/accounting_localization