[IMP] studio: complete update of Studio

The goal is to make the Studio users doc a sort of encyclopedia to accompany tutorials.
The doc isn't to explain the basics - or just briefly, as introductions - but instead to
give a full overview of all the available options.

closes odoo/documentation#2531

Task: 2817981
X-original-commit: c8ea9703f7
Signed-off-by: Antoine Vandevenne (anv) <anv@odoo.com>

content/applications/productivity/studio.rst

@@ -1,21 +1,30 @@
-:nosearch:
 :show-content:
 :hide-page-toc:
-:show-toc:
 
 ======
 Studio
 ======
 
-Learn all you need in order to build custom applications: customize views, create specific reports,
-automate actions, define approval workflows, etc.
-
-.. seealso::
-   - `Odoo Tutorials: Studio <https://www.odoo.com/slides/studio-31>`_
-
 .. toctree::
    :titlesonly:
 
-   studio/concepts
-   studio/use_cases
-   studio/how_to
+   studio/fields
+   studio/views
+   studio/models_modules_apps
+   studio/automated_actions
+
+Studio is a toolbox that allows you to customize Odoo without coding knowledge. For example, you
+can, on any app, add or modify:
+
+- :doc:`Fields <studio/fields>`
+- :doc:`Views <studio/views>`
+- :doc:`Models <studio/models_modules_apps>`
+- :doc:`Automated actions <studio/automated_actions>`
+- PDF reports
+- Approval rules
+- Security rules
+
+Or you can :doc:`build an app from scratch <studio/models_modules_apps>`.
+
+.. seealso::
+   - `Odoo Tutorials: Studio <https://www.odoo.com/slides/studio-31>`_