Update documentation front page (index.rst)

Author: maarten-ic

docs/source/index.rst

@@ -34,35 +34,31 @@ It provides:
    lazy_loading
    mdsplus
 
-.. toctree::
-   :hidden:
-   :caption: IMASPy training courses
-
-   courses/basic_user_training
-   courses/advanced_user_training
+The README is best read on :src:`#imaspy`.
 
 
-README
+Manual
 ------
 
-The README is best read on :src:`#imaspy`.
+.. toctree::
+   :caption: IMASPy training courses
+   :maxdepth: 2
 
-For developers
-==============
+   courses/basic_user_training
+   courses/advanced_user_training
 
-* :doc:`api`
-* :doc:`api-hidden`
 
 .. toctree::
-   :hidden:
    :caption: API docs
+   :maxdepth: 1
 
    api
    api-hidden
 
 
 .. toctree::
    :caption: IMASPy development
+   :maxdepth: 1
 
    benchmarking