Doc: Update RTD landing page

Add a bit of content. #95.

doc/index.rst

@@ -6,14 +6,55 @@
 Welcome to petab-select's documentation!
 ========================================
 
+PEtab Select brings
+`model selection <https://en.wikipedia.org/wiki/Model_selection>`_ to
+`PEtab <https://petab.readthedocs.io/>`_. PEtab Select comprises file
+formats, a Python library and a command line interface.
+
+Model selection is the process of choosing the best model from a set of
+candidate models. PEtab Select provides a standardized and compact way to
+specify the candidate model space, implements a number model selection
+algorithms and criteria.
+
+Supported model selection algorithms:
+
+* brute force
+* forward selection
+* backward selection
+* FAMoS
+
+Supported model selection criteria:
+
+* (corrected) Akaike Information Criterion (AIC / cAIC)
+* Bayesian Information Criterion (BIC)
+* ...
+
+Model calibration is performed outside of PEtab Select. For example,
+PEtab Select is well-integrated with
+`pypesto <https://pypesto.readthedocs.io/>`_
+(`model selection example <https://pypesto.readthedocs.io/en/latest/example/model_selection.html>`_).
+Other model calibration tools can easily be integrated using the provided
+Python library or command line interface.
+
+Installation
+------------
+
+The Python 3 package provides both the Python 3 and command-line (CLI)
+interfaces, and can be installed from PyPI, with
+
+.. code-block:: bash
+
+    pip install petab-select
+
+
 .. toctree::
    :maxdepth: 2
    :caption: Contents:
 
+   problem_definition
    examples
    Test Suite <test_suite>
    api
-   problem_definition
 
 
 Indices and tables