[ADD] ecommerce: performance monitoring

Adding a doc page on performance monitoring and analysis for eCommerce
websites

closes odoo/documentation#4015

Taskid: 3246984
X-original-commit: 4c623b69b1
Signed-off-by: Platteau Xavier (xpl) <xpl@odoo.com>
Signed-off-by: Castillo Jonathan (jcs) <jcs@odoo.com>

content/applications/websites/ecommerce/ecommerce_management.rst

@@ -10,3 +10,4 @@ eCommerce management
    ecommerce_management/order_handling
    ecommerce_management/customer_accounts
    ecommerce_management/customer_interaction
+   ecommerce_management/performance

content/applications/websites/ecommerce/ecommerce_management/performance.rst

@@ -0,0 +1,50 @@
+======================
+Performance monitoring
+======================
+
+Odoo integrates a variety of tools to analyze and improve the performance of your eCommerce
+website.
+
+Performance analysis tools
+==========================
+
+Data monitoring
+---------------
+
+**Website** allows monitoring and analysis of the sales performance of your eCommerce. To access the
+**reporting view**, go to :menuselection:`Website --> Reporting`. This dashboard helps you monitor
+everything related to sales, such as sales performance per product, category, day, etc.
+
+.. image:: reporting/reporting.png
+   :align: center
+   :alt: Performance reporting of eCommerce
+
+By clicking :guilabel:`Measures`, you can select the type of measurement used, such as:
+
+- :guilabel:`Margin`;
+- :guilabel:`Qty Invoiced`;
+- :guilabel:`Untaxed Total`;
+- :guilabel:`Volume`;
+- ...
+
+Other options include **multiple views (Pivot, etc.), comparison** by periods or years, and directly
+:guilabel:`insert in spreadsheet`, etc.
+
+Analytics
+---------
+
+It is possible to link your Odoo website with Google Analytics. To do so, go to
+:menuselection:`Website --> Configuration --> Settings` and scroll to the :guilabel:`SEO` section.
+Then, enter your **ID** in the :guilabel:`Measurement ID` field.
+
+If you are still using **Universal Analytics**, it can directly be added by injecting the code in
+the HTML header and body using the website builder. All metrics from Google Analytics and Universal
+Analytics can be seen directly within Odoo.
+
+Alternatively, Odoo offers the possibility to use another service, **Plausible.io**. Plausible.io is
+a simple and privacy-friendly alternative to Google Analytics. Everything can be managed directly in
+Odoo, there is no need to visit Plausible.io's website to access your metrics.
+
+.. seealso::
+   - :doc:`/applications/websites/website/optimize/google_analytics`
+   - :doc:`/applications/websites/website/optimize/plausible`