[MOV] general: renames "odoo_basics" into "users" + split content

This commit is part of a larger work to improve the documentation's
structure. The toctree structure used to add levels to create categories
and make the structure visually more understandable.
With the new version of the documentation, plenty of these categories
are now redundant.

Since other docs were moved away from the section "basics" with previous
commits, this category is renamed "users settings"
This commit:
- renames "basics" into "users settings"
- moves the content from "odoo_basics/users" to "users"
  - it moves the content about "access rights" to a child doc

task-2535899

content/applications/productivity/studio/how_to/reports.rst

@@ -34,10 +34,10 @@ them. Fields with related objects have their directives shown on *Field Expressi
 | Under **Visible if**, define the rule(s) to set visibility conditions to fields.
 | Example: if choosing to display a product image, you could set a visibility rule to only display
   the ones that are *set* in the product form, avoiding having a plain icon when they are not set.
-| **Visible for** is used to set which :doc:`groups </applications/general/odoo_basics/users>`
-  can have access to specific elements in the report. **Limit visibility to groups**, under
-  *Report*, sets the visibility of the report to specifics groups, meaning that users belonging to
-  other groups do not see the same final document.
+| **Visible for** is used to set which :doc:`groups </applications/general/users>` can have access
+  to specific elements in the report. **Limit visibility to groups**, under *Report*, sets the
+  visibility of the report to specifics groups, meaning that users belonging to other groups do not
+  see the same final document.
 
 .. image:: media/reports/limit_visibility.png
    :align: center